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[studies of yersinia pestis in wild animals captured in ankara, konya and nevsehir].no yersinia pestis could be isolated, by culturing and by inoculations to 1212 guinea-pigs and 150 mice; from 623 citellus, 41 mus musculus, 55 microtus, 442 meriones, 70 rattus rattus, 56 turtle, 89 hare, 1 hamster, 1 hedgehog, 1 sea snake, altogether 790 dead, 589 alive, i.e. 1379. wild animals captured in ankara, konya (karapinar), urfa (akçakale) and in nevşehir. in 141 sera taken from citellus captured alive, and in 174 sera taken from guinea-pigs inoculated with spleen, liver and kidney su ...1976933892
[adenylate cyclase. a possible factor in the pathogenicity of yersinia pestis].biological effect of homogenous preparation of y. pestis adenylate cyclase on eucaryotic cells was studied. adenylate cyclase, added (7.5 x 10(8) g/ml) to guinea pig macrophages lowers the level of chemiluminescence to 50-70%, has an appreciable cytotoxic effect on peritoneal macrophages and suppresses phosphorylation processes of leucocyte proteins from white mice. the experimental results obtained allow to suggest y. pestis adenylate cyclase to be a pathogenic factor, contributing to the devel ...19921596952
surface-exposed antigenic determinants in outer membranes of wild yersinia pestis isolates.immunogenic surface exposed envelope proteins of yersinia pestis strains were investigated with sds-page and immunoblots with antisera of immunized guinea pigs and convalescent patients. the sarkosyl-insoluble outer membrane proteins (omps) of three human isolates and one laboratory strain of y. pestis grown in different rich media to exponential or stationary phase, and cultivated at 28 degrees c or 37 degrees c, were assayed for the presence of immunogenic peptides. seven guinea-pig sera immun ...19911724154
[the heterogeneity of the alveolar macrophages of guinea pigs immunized subcutaneously with a vaccinal strain of yersinia pestis].the study of alveolar macrophages obtained from guinea pigs at different periods after the subcutaneous immunization with y. pestis vaccine strain has revealed the heterogeneity of these macrophages in their bactericidal activity with respect to y. pestis and in their resistance to the cytopathic action of this microorganism, as well as in the content of lysosomes and in the expression of receptors on the cell surface. the study has shown that subcutaneous immunization does not lead to the redis ...19911801486
[the effect of a plague pathogen plasmid on lethality and immunogenicity].on the model of yersinia transconjugants (yersinia pestis, yersinia pseudotuberculosis, yersinia enterocolitica) carrying the conjugative cointegrates containing the 47 and 65 md plasmids from yersinia pestis the data were obtained on the different affects of the latter plasmids on the lethality and immunogenicity conferred by the host bacterial cells. the plasmid effects were drastically different during bacterial infection in mice or guinea pigs. the possibility of appearance of the recombinan ...19911857372
persistent survival of attenuated yersinia pestis organisms with coexistence of chondroitin sulfate colloidal iron within guinea pig macrophages as an initial step of the induction of potent antiplague immunogenesis. 19911935095
[the phenomenon of pilus formation in the interaction of yersinia pestis with macrophages in experimental animals].according to the data of the enzyme immunoassay, adhesion pili were expressed by y. pestis cells eb76 after their cultivation in media with ph similar to that of phagolysosomes. the expression of adhesion pili was found to occur 18 hours after the contact of apiliate cells eb76 with a monolayer of native, but not inactivated (at 56 degrees c for 30 minutes) macrophages of the peritoneal exudate of white mice and guinea pigs. purified adhesion pili possessed cytotoxic action and inhibited the dig ...19901973326
[the effect of the adhesion pili of yersinia pestis on the physiological activity of the leukocytes and macrophages in experimental animals].the data on the influence of the preparation of y. pestis adhesion pili on peritoneal macrophages in white mice and guinea pigs are presented. y. pestis adhesion pili have been found to induce the dose-dependent increase of cell chemiluminescence. they have also been found to induce a number of biochemical changes in target cells: the secretion of myeloperoxidase, an increase in the activity of camp-dependent protein kinases.19901978453
[the isolation and characteristics of variant plague microbes not producing the capsular antigen].fifteen stable variants of yersinia pestis strains exhibiting different degrees of virulence for white mice and guinea pigs were obtained. multiple passages of the organisms at 37 degrees c in a fluid nutrient medium containing antiplague agglutinating serum were found to be the most efficient method for obtaining noncapsular forms of the plague agent. acquisition of the fra(-) phenotype both by wild and laboratory strains was not associated with a loss of the high-molecular plasmid by cells but ...19902097497
[the expression of fc gamma receptors on the surface of macrophages activated by a vaccinal strain of yersinia pestis].the expression of fc gamma r on the surface of macrophages in the process of antiplague immunity formation is analyzed. the stud is performed on the alveolar and peritoneal macrophages obtained from intact and immunized guinea pigs in different periods after vaccination (the 1st, 7th, 14th and 21st day). it is established that during the formation of the antiplague immunity there occurs activation of macrophages which is accompanied by an increase of the fc gamma r expression on the outer surfac ...19902142978
[the phagocytic activity of peritoneal macrophages in relation to yersinia pestis with defective and complete fra genes].in vitro study of phagocytosis has shown that in guinea pigs fraction 1 is conducive to the ingestion of y. pestis by macrophages, to survival and proliferation of y. pestis cells in these macrophages, as well as to their specific transformation leading to their increased ingestive and bactericidal activity with respect to y. pestis. in mice the role of fraction 1 in phagocytosis has proved to be less significant.19902386004
[prostaglandins and cyclic nucleotides in the dynamic development of an experimental poisoning syndrome caused by yersinia pestis lipopolysaccharide].this work deals with the influence of y. pestis lipopolysaccharide (lps), introduced intraperitoneally in a dose of 2 ld50, on the content of prostaglandins (pg), such as pge, pgf2 alpha and 6-keto-pgf1 alpha, thromboxane, camp and cgmp in the liver, lungs and blood plasma of guinea pigs in the process of the development of experimental intoxication. the content of thromboxane in blood plasma increased 2.4-fold in 2 hours after intoxication and remained elevated for as long as 5 hours. other par ...19892711790
[yersinia pestis l-forms in rodents and ectoparasites].y. pestis l-forms and bacterial forms persist in the body of great gerbils for 40 days. l-forms are poorly phagocytized and can persist in phagocytes for a long time. in guinea pigs immunized with vaccine ev, y. pestis antigen could be detected till day 160. an unstable l-form was isolated from ornithodoros mites 3 years after their experimental infection with y. pestis. bacterial forms persist in mites for 1-3 years. for 5 years y. pestis antigen is regularly detected in a high percentage of mi ...19892728699
[the mutagenic effect of polymorphonuclear leukocytes on yersinia pestis].as the result of in vitro experiments, y. pestis auxotrophic mutants have been obtained under the influence of polymorphonuclear lymphocytes obtained from guinea pigs, previously immunized with y. pestis strain ev. the mutagenic effect has been found to occur at minute 45 of phagocytosis. the control treatment of the bacteria with the lysate of neutrophils, homologous serum, penicillin (antibiotic-influenced selection) has not been found to lead to the appearance of auxotrophicity. these data su ...19892735164
[genetic analysis and simulation of the virulence of yersinia pestis].the genetic analysis of y. pestis virulence factors accomplished in the 358 strain isogenic system allowed us to determine a minimal set of known factors providing pathogenicity. the combination of chromosomal marker pgm+ and calcium dependence plasmid (pcad) is shown to be sufficient for preserving the virulence of y. pestis. experimental modelling of virulence in this microorganism by the genetic exchange methods was carried out. the reduced virulence of the strains pgm+ and pcad+ for guinea p ...19892811911
[evaluation of the modulating action of yersinia pestis adenylate cyclase on guinea pig peritoneal leukocytes using chemiluminescence].the biological action of y. pestis adenylate cyclase on peritoneal leukocytes of guinea pigs has been studied by means of chemiluminescence. y. pestis adenylate cyclase is supposed to contribute to the "oxidation" explosion of phagocytes in plague.19872823508
[evaluation of vaccinal immunogenesis by the peroxidase method].the possibility of evaluating functional immunomorphogenesis in the course of the vaccinal process after the injection of conjugated and live brucellosis vaccines, as well as conjugated plague antigen and yersinia pestis strain ev, to guinea pigs has been shown by means of the direct and two-layer variants of the immunoperoxidase assay. the dynamics of the accumulation of globulin-producing cells in the immunocompetent organs and the time course of immunoglobulin titers in the peripheral blood a ...19863548171
comparison of the immune response to three different yersinia pestis vaccines in guinea pigs and langurs. 19744207626
live, attenuated yersinia pestis vaccine: virulent in nonhuman primates, harmless to guinea pigs. 19744207627
in vivo comparison of avirulent vwa- and pgm- or pstr phenotypes of yersiniae.the abilities of yersinia pestis to undergo restriction in ca2+-deficient medium with concomitant production of v and w antigens (vwa+) and to absorb exogenous pigments (pgm+) are established virulence factors. mutation of y. pestis to pgm- is known to promote resistance to pesticin (pstr) and reduced lethality by peripheral routes of injection. vwa+ pgm- isolates of y. pestis were shown in this study to retain virulence in mice when injected intravenously. although pgm- in appearance, wild-type ...19846365786
[an increase in the virulence of yersinia pestis bacteria when the cells are incubated in hemolyzed human erythrocytes].the incubation of y. pestis, the causative agent of plague, in hemolyzed human red blood cells at 37 degrees c for 3 hours enhanced the virulence of vaccine strain ev76 in white mice and guinea pigs and decreased the ld50 of attenuated strains. the phenomenon of increased virulence has been observed only in case of the combined injection of bacteria with the incubation medium. the virulence of y. pestis cells, introduced alone after such treatment, has proved to remain at the same level.19938067110
[the activation of yersinia pestis "murine" toxin and endotoxin by hemolyzed erythrocytes from mammalian blood].y. pestis "mouse" toxin and endotoxin have been found to be capable of being activated with hemolyzed mammalian red blood cells. the ld50 of the activated endotoxin decreases 5-10 times in comparison with the initial preparation. the ld50 of the activated "mouse" toxin decreases 5 times. as revealed in this study, the joint introduction of nonlethal doses of "mouse" toxin and endotoxin is highly toxic for white mice and guinea pigs. the presence of both "mouse" toxin and endotoxin in the toxic m ...19958525723
[the antibody spectrum after the inoculation of sensitive animals with yersinia pestis and yersinia pseudotuberculosis bacteria].antibody spectra in the sera of guinea pigs and white mice infected with y. pestis and y. pseudotuberculosis, the causative agents of plague and pseudotuberculosis, were determined with the use of immunoblotting. the amount of antigens, found to produce humoral immune response both in plague and in pseudotuberculosis was, on the whole, considerably less (5-6 times) in white mice than in guinea pigs. the animals were found to produce antibody response to plasmid-specific (yop) y. pestis antigens ...19968701667
virulence of ppst+ and ppst- strains of yersinia pestis for guinea-pigs.guinea-pigs were infected subcutaneously or by respiratory challenge with plasmid-containing (ppst+pcad+pfra+) yersinia pestis strain 358 and its ppst-pcad+pfra+, ppst+pcad+pfra- and ppst-pcad+pfra- derivatives, grown in vitro at 28 degrees c or at 37 degrees c. lack of plasmid ppst did not lead to an increase in ld50 with either route of challenge. when the virulence of the four y. pestis strains grown at the two temperatures was compared, the ld50 values of those grown at 37 degrees c were low ...19968958247
murine toxin of yersinia pestis shows phospholipase d activity but is not required for virulence in mice.purified murine toxin (ymt) of yersinia pestis is highly toxic for mice and rats but less active in other animals such as guinea pigs, rabbits, dogs and monkeys. this suggested that ymt contributes to the very low infectious dose of y. pestis in mice. the gene encoding ymt (ymt) is localised on the 100-kb plasmid pfra, which is unique for y. pestis. sequence analysis revealed that ymt showed homology to proteins of the phospholipase d (pld) superfamily of proteins. y. pestis strains expressing y ...200011111930
[lectin of yersinia pestis vaccine strain ev and its immunological properties].as the result of the chromatographic separation of y. pestis ev membrane proteins, a protein fraction with hemagglutinating activity was obtained. the isolated preparation was glycoprotein with a molecular weight of 22 kd, contained 16% of carbohydrates and exhibited thermolabile properties. the determination of the carbohydrate specificity of this glycoprotein revealed that it belonged to the class of lectins. changes in the content of 11 corticosteroids and the population composition of lympho ...200312630354
retrospective study of a plague outbreak by multiplex-pcr.to determine the effectiveness of multiplex-pcr in yersinia pestis identification in samples preserved in cary & blair medium and to evaluate if this technique would uncover y. pestis-positives among culture-negative samples.200314633104
[experimental study on the possibility of using live tularemia vaccine to increase resistance to heterologous infection disease].in experiments on guinea pigs immunized with francisella tularensis 15, or live tularemia vaccine (ltv), the level of heterologous protective effect to dangerous infectious diseases caused by yersinia pestis, burkholderia pseudomallei, b. mallei, mycobacterium tuberculosis was studied. the study revealed that during the first 4 weeks after the subcutaneous immunization with ltv the level of resistance of the immunized animals to heterologous infective agent reliably increased as indicated by the ...200415188557
[electrophoretic mobility and energy charge of the adenyl system of blood lymphocytes in guinea pigs immunized against plague with strain yersinia pestis ev subcultures with different immunogenicity].the injection of highly immunogenic vaccine strain yersinia pestis ev, line niieg, into guinea pigs was accompanied, as early as 24 hours after this injection, by a drop in the electrophoretic mobility of the main amount of lymphocytes, significant shifts in the content and quantitative relation of adenine nucleotides in the mixed lymphocyte population, as well as t and b lymphocytes after their preparative electrophoretic sorting. the immunizatiom of guinea pigs with strain ev of the japanese l ...200516279538
scavenging by mammalian carnivores on prairie dog colonies: implications for the spread of plague.plague causes mass mortality of prairie dogs (cynomys ludovicianus) in shortgrass steppe. although the pathogen, the bacterium yersinia pestis, is spread within colonies by flea bites or contact between infected hosts, it is unclear how y. pestis is transported over long distances between isolated colonies. one possibility is that wideranging, plague-resistant mammalian carnivores pick up fleas when scavenging prairie dog carcasses. using guinea pigs as surrogates for prairie dogs, we compared h ...200918945188
comparison of mouse, guinea pig and rabbit models for evaluation of plague subunit vaccine f1+rv270.in this study, a new subunit vaccine that comprised native f1 and recombinant rv270 was evaluated for protective efficacy using mouse, guinea pig and rabbit models in comparison with the live attenuated vaccine ev76. complete protection against challenging with 10(6) colony-forming units (cfu) of virulent yersinia pestis strain 141 was observed for mice immunized with the subunit vaccines and ev76 vaccine. in contrast, the subunit vaccine recipes vii (f1-20 microg+rv270-10 microg) and ix (f1-40 ...201020079562
[role of histamine receptors of mouse and guinea pig peritoneal leukocytes in the pathogenetic effect of yersinia pestis adenylate cyclase].the effect of purified preparation of adenylate cyclase isolated from y. pestis on peritoneal leukocytes of white mice and guinea pigs was investigated. y. pestis adenylate cyclase was shown to accomplish its pathogenic action via histamine-specific receptors on the surface of eukaryotic cells. the involvement of h1 and h2 histamine receptors on target cells in the adenylate cyclase action leading to development of plague infection is discussed.19921446035
protection afforded by fluoroquinolones in animal models of respiratory infections with bacillus anthracis, yersinia pestis, and francisella tularensis.successful treatment of inhalation anthrax, pneumonic plague and tularemia can be achieved with fluoroquinolone antibiotics, such as ciprofloxacin and levofloxacin, and initiation of treatment is most effective when administered as soon as possible following exposure. bacillus anthracis ames, yersinia pestis co92, and francisella tularensis schu s4 have equivalent susceptibility in vitro to ciprofloxacin and levofloxacin (minimal inhibitory concentration is 0.03 μg/ml); however, limited informat ...201021127743
[biological activity of the components of f1-antigen of yersinia pestis].components of the capsule antigen (baker), described early as f17, f18, f43, flp, which positively reacts with commercial poly- and monoclonal antifractions plague diagnosticums were studied. differences and their impacts on vaccine bacteria survival within peritoneal macrophages, guinea pigs and protection of white mice after immunization and fast protection against plague were shown. hemolytic, cytolytic and hemo- and cytoagglutinations activities of lipoprotein (flp) and capacity of glycoprot ...200616830596
protection conferred by recombinant yersinia pestis antigens produced by a rapid and highly scalable plant expression system.plague is still an endemic disease in different regions of the world. increasing reports of incidence, the discovery of antibiotic resistance strains, and concern about a potential use of the causative bacteria yersinia pestis as an agent of biological warfare have highlighted the need for a safe, efficacious, and rapidly producible vaccine. the use of f1 and v antigens and the derived protein fusion f1-v has shown great potential as a protective vaccine in animal studies. plants have been exten ...200616410352
[apoptosis of phagocytes as one of the probable mechanisms of the pathogenetic action of yersinia pestis "mouse" toxin].apoptosis was evaluated by characteristic morphological changes of cells in preparations stained with histological dyes and in live preparations, as well as by dna degradation, colorimetrically detected with the use of the diphenylamine reagent. "mouse toxin" (mt) was found to have a pronounced apoptogenic action with respect to the phagocytic cells of mice, but not guinea pigs. macrophages were affected by this action stronger than neutrophils, and in both cases this effect was dose dependent. ...200515881939
[the virulence of yersinia pestis strains in serial-passage in guinea pig peritoneal macrophages].the cultivation of y.pestis virulent strains in macrophages of guinea pigs has been found to enhance their virulence, decreased during storage, and to increase their antiphagocytic and cytopathic properties. this effect makes it expedient to recommend the passage of y.pestis through peritoneal macrophages of guinea pigs with the aim of stabilizing their virulence. the proposed method reduces the duration of investigation 6 times, decreases the number of experimental animals used in the investiga ...19968820669
an aroa mutant of yersinia pestis is attenuated in guinea-pigs, but virulent in mice.this study describes a pcr-based approach for the production of a rationally attenuated mutant of yersinia pestis. degenerate primers were used to amplify a fragment encoding 91.45% of the aroa gene of y. pestis mp6 which was cloned into puc18. the remainder of the gene was isolated by inverse pcr. the gene was sequenced and a restriction map was generated. the y. pestis aroa gene had 75.9% identity with the aroa gene of yersinia enterocolitica. the cloned gene was inactivated in vitro and reint ...19968757748
[immunogenicity of yersinia pestis grown on nutrient media at 28 and 37 degrees c].the immunogenicity of y. pestis strain ev, grown in yeast-casein medium, yeast medium with hottinger digest and yeast medium with sunflower-seed protein at 28 degrees c and 37 degrees c, for guinea pigs and white mice has been studied. as revealed in this study, these media ensure the formation of highly immunogenic populations of y. pestis strain ev and, therefore, can be used for growing y. pestis vaccine strains. considerable fluctuations in the content of such highly protective antigen as fr ...19873673377
[changes in the "latent" virulence of a vaccinal strain of yersinia pestis multiplying within macrophages].the multiplication of y. pestis vaccinal strain inside peritoneal macrophages of guinea pigs and white mice in vitro leads to an essential increase in its latent virulence. this effect is most pronounced when guinea pig macrophages are used. changes in the latent virulence of y. pestis vaccinal strains, occurring in the process of their passage inside macrophages in vitro, correlate with those observed in vivo, i.e. in animal experiments.19883206961
selective protective potency of yersinia pestis δnlpd mutants.it has recently been shown that the nlpd lipoprotein is essential to yersinia pestis virulence and that subcutaneous administration of the nlpd mutant could protect mice against bubonic and pneumonic plague better than the ev vaccine strain [plos one 2009. v. 4. № 9. e7023]. in this study, similar δnlpd mutants were generated on the basis of other y. pestis parent strains, including strains from the subspecies microtus, which is avirulent to guinea pigs and humans. comparative testing confirmed ...201725927007
[protein expression of yersinia pestis during changes due to long-term cultivation in vivo].the electrophoretic study of yersinia pestis proteins made possible to find the significant modification of yersinia pestis polypeptide specters when the bacteria were cultivated in semi-penetrable cells implanted into the guinea pigs peritoneum. the proteinogramms of the isolates from the implanted cells lacked the stained bands characteristic of yersinia pestis cells grown in vitro and contained the new polypeptides absent from the bacteria grown on the hottinger agar plates. the difference wa ...19911784300
yersinia pestis: correlation of ultrastructures and immunological status.ultrastructural identification and localization of the fraction 1 "envelope" antigen in the plague bacillus yersinia pestis were the primary objectives of this brief study. the antigenicity of extra-cellular material between the bacilli in undisturbed cultured colonies and that of the pathogen per se were measured and correlated by means of the semi quantitative complement fixation method after incubation for 72 h at 37 c. when the amount of extracellular substance in wild-type t1 (virulent) bac ...19751095487
evaluation of live attenuated plague vaccines in praomys (mastomys) natalensis.a live attenuated yersinia pestis vaccine designated ev76-51f, which had previously been shown to be pathogenic in vervet monkeys but not in guinea pigs, was tested in the multimammate mouse praomys (mastomys) natalensis. doses of 10(6) viable organisms inoculated subcutaneously as either a lyophilized suspension or an agar-grown culture resulted in vaccination fatalities in praomys but not in white mice. hemagglutinating antibodies to the fraction 1 antigen were not stimulated by doses lower th ...1977908624
a yersinia pestis lpxm-mutant live vaccine induces enhanced immunity against bubonic plague in mice and guinea pigs.the lpxm mutant of the live vaccine yersinia pestis ev niieg strain synthesising a less toxic penta-acylated lipopolysaccharide was found to be avirulent in mice and guinea pigs, notably showing no measurable virulence in balb/c mice which do retain some susceptibility to the parental strain itself. twenty-one days after a single injection of the lpxm-mutant, 85-100% protection was achieved in outbred mice and guinea pigs, whereas a 43% protection rate was achieved in balb/c mice given single lo ...200717913308
protective efficacy of a fully recombinant plague vaccine in the guinea pig.a fully recombinant sub-unit vaccine comprising the protein antigens rf1 + rv has been demonstrated to protect immunised guinea pigs against exposure to 10(5) colony-forming units (cfu) of virulent yersinia pestis. additionally, igg purified from rf1 + rv-immunised guinea pig serum, protected the mouse by passive immunisation against challenge with y. pestis whereas igg purified from the serum of guinea pigs immunised with a licensed killed whole cell (kwc) vaccine for plague, protected less wel ...200312922126
[evaluation of hypoxic state in experimental animals induced by yersinia pestis antigens].some characteristics of purine metabolism in experimental animals (white mice, clawed jirds and guinea pigs), injected intraperitoneally with y. pestis "murine" toxin and capsular antigen (fraction 1), were studied. under the influence of sublethal doses of these antigens increased levels of guanine and xanthine in blood were noted. changes in the content of xanthine oxidase in cells were insignificant. in white mice and clawed jirds the activity of succinate dehydrogenase decreased under the ac ...200212525005
[the properties of the cellular surface of yersinia pestis strain ev and its achromogenic variants].the comparative study of the properties of the surface of vaccine strain y. pestis ev and its achromogenic variants (av) differing from the initial strain by decreased immunogenicity and by the morphology of colonies, has been made. the achromogenicity of y. pestis colonies has been shown to correlate with the loss of the outer membrane protein with a molecular weight 22 kd. the synthesis of this protein is determined by chromosomal genes. av have been found to have different sensitivity to bact ...200010925864
[in vitro influence of biologically active factors of microorganisms on antibiotic susceptibility of yersinia pestis].to estimate the in vitro susceptibility of the plague microbe to chemotherapeutics, various experimental models with the maximum closeness to the host conditions were tested. the tests included the assay of the drug antibacterial activity against the plague microbe by the method of two-fold dilutions in biological fluids i.e. human normal (nonimmune) serum (hns) and guinea pig heparinized blood. hottinger broth was used as the control. it was shown that any system used for estimation of the drug ...19979463297
[the protective activity of the adhesion pili of yersinia pestis].y. pestis adhesion pili (ap) in the native form and in the subunit form, used for immunization in one or two injections in a dose of 12-100 mu g on aluminum hydroxide, did not protect white mice and guinea pigs from experimental y. pestis infection. the study revealed that ap produced a pronounced cytotoxic effect on macrophages and practically no influence on leukocytes. this result was confirmed in the study of luminol-dependent chemiluminescence and in the analysis of 5'-nucleotidase activity ...19958525726
[the significance of pesticin 1 for the virulence and immunogenicity of yersinia pestis].the work deals with the study of the virulent and immunogenic properties of y. pestis strains which lost their capacity for producing pesticine 1 as the result of the insertion of a tn-like element into the 6-md plasmid responsible for this property. the "switching-off" of gene pst induced a decrease in the virulence of y. pestis injected subcutaneously into white mice and guinea pigs and had no influence on its level of immunogenicity for white mice. a suggestion was made that pesticine 1 playe ...19911659072
plant-derived recombinant f1, v, and f1-v fusion antigens of yersinia pestis activate human cells of the innate and adaptive immune system.plague is still endemic in different regions of the world. current vaccines raise concern for their side effects and limited protection, highlighting the need for an efficacious and rapidly producible vaccine. f1 and v antigens of yersinia pestis, and f1-v fusion protein produced in nicotiana benthamiana administered to guinea pigs resulted in immunity and protection against an aerosol challenge of virulent y. pestis. we examined the effects of plant-derived f1, v, and f1-v on human cells of the ...200919309560
an outbreak of plague including cases with probable pneumonic infection, ecuador, 1998.during february and march of 1998, 12 sudden deaths were reported among residents of a high-andean community in ecuador. all 12 fatalities were members of the same extended family and some had apparent exposure to sick guinea-pigs. following an initial investigation by public health officials, an additional death was reported in a nearby community in april, also associated with exposure to sick guinea-pigs. blood samples from humans, dogs, and a rodent were tested for antibody to the f1 antigen ...200011127240
pathogenicity and immunogenic efficacy of a live attentuated plaque vaccine in vervet monkeys.a live attenuated yersinia pestis (pasteurella pestis) vaccine strain designated ev51f, which had been passaged through guinea pigs previously treated with ferrous sulfate, was shown to be pathogenic for african green vervet monkeys (cercopithecus aethips pygerythrus), but not for guinea pigs. the bacilli multiplied in the monkeys, as shown by positive blood cultures, caused an elevation of white cell counts and rectal temperatures, and resulted in death of 26% (13/50) of animals. postmortem fin ...19734206343
prevention of pneumonic plague in mice, rats, guinea pigs and non-human primates with clinical grade rv10, rv10-2 or f1-v vaccines.yersinia pestis causes plague, a disease with high mortality in humans that can be transmitted by fleabite or aerosol. a us food and drug administration (fda)-licensed plague vaccine is currently not available. vaccine developers have focused on two subunits of y. pestis: lcrv, a protein at the tip of type iii secretion needles, and f1, the fraction 1 pilus antigen. f1-v, a hybrid generated via translational fusion of both antigens, is being developed for licensure as a plague vaccine. the rv10 ...201121763383
recent findings regarding maintenance of enzootic variants of yersinia pestis in sylvatic reservoirs and their significance in the evolution of epidemic plague.despite the widespread presence of bubonic plague in sylvatic reservoirs throughout the world, the causative agent (yersinia pestis) evolved in its present form within the last 20,000 years from enteropathogenic yersinia pseudotuberculosis. comparison of the genomes from the two species revealed that y. pestis possesses only a few unique plasmid-encoded genes that contribute to acute disease, whereas this organism has lost about 13% of the chromosomal genes that remain active in y. pseudotubercu ...201020158336
[yersinia pestis superoxide dismutase].superoxide dismutases with molecular weight of 65-67 and 200 kd have been identified in yersinia pestis ev cells. these enzymes have some differences in antigenic specificity, resistance to heating and inhibitors (cyanides and hydrogen peroxide). the activity of y. pestis superoxide dismutase is a thermoinducible sign unassociated with the presence of residual plasmids of the bacilli. superoxide dismutase can be released from the cells into liquid culture medium. patients inoculated with live pl ...19957542952
plague in guinea pigs and its prevention by subunit vaccines.human pneumonic plague is a devastating and transmissible disease for which a food and drug administration-approved vaccine is not available. suitable animal models may be adopted as a surrogate for human plague to fulfill regulatory requirements for vaccine efficacy testing. to develop an alternative to pneumonic plague in nonhuman primates, we explored guinea pigs as a model system. on intranasal instillation of a fully virulent strain, yersinia pestis co92, guinea pigs developed lethal lung i ...201121406168
comparison of immunological responses of plague vaccines f1+rv270 and ev76 in chinese-origin rhesus macaque, macaca mulatta.the subunit vaccine sv1 (20 μg f1+10 μg rv270) has been identified as the optimal formulation in mice, which provided a good protection against plague in mice, guinea pigs and rabbits. to compare sv1 and sv2 (200 μg f1+100 μg rv270) with live attenuated vaccine ev76, antibody responses, protective efficacy, cytokines (ifn-γ, tnf-α, il-2, il-4, il-10 and il-12) production, cd4/cd8 ratio and cd69(+) t-cell activation marker were determined in sera of the immunized chinese-origin rhesus macaques, m ...201021039737
functional characterization and biological significance of yersinia pestis lipopolysaccharide biosynthesis genes.in silico analysis of available bacterial genomes revealed the phylogenetic proximity levels of enzymes responsible for biosynthesis of lipopolysaccharide (lps) of yersinia pestis, the cause of plague, to homologous proteins of closely related yersinia spp. and some other bacteria (serratia proteamaculans, erwinia carotovora, burkholderia dolosa, photorhabdus luminescens and others). isogenic y. pestis mutants with single or double mutations in 14 genes of lps biosynthetic pathways were construc ...201121999543
[the experiments conducted by japanese on human guinea pigs, and the use of biological weapons during the sino-japanese war (1937-1945)].starting from the end of the nineteenth century, and during the first four decades of the past century, japan showed considerable military expansion, on the back of a pan-asiatic and imperialistic ideology, comparable only to those expressed by wilhelmian and nazi germany. this growth led to japan playing an extremely important role in the asia-pacific continent, which unavoidably brought the country onto a collision course with the british empire and the united states of america. the japanese g ...201425269971
two isoforms of yersinia pestis plasminogen activator pla: intraspecies distribution, intrinsic disorder propensity, and contribution to virulence.it has been shown previously that several endemic y. pestis isolates with limited virulence contained the i259 isoform of the outer membrane protease pla, while the epidemic highly virulent strains possessed only the t259 pla isoform. our sequence analysis of the pla gene from 118 y. pestis subsp. microtus strains revealed that the i259 isoform was present exclusively in the endemic strains providing a convictive evidence of more ancestral origin of this isoform. analysis of the effects of the i ...201627936190
pathology and pathogenesis of yersinia pestis.various types of animal models of plague have been developed, including mice, rats, guinea pigs, and nonhuman primates. studies have indicated that rodent and nonhuman primate models of pneumonic plague closely resemble the human disease and that the pathologic changes that occur during bubonic plague are very similar in rodents, nonhuman primates, and humans. in this section, the pathological changes caused by y. pestis in different animal models are described. the bacterium y. pestis causes de ...201627722864
yersinia pestis caf1 protein: effect of sequence polymorphism on intrinsic disorder propensity, serological cross-reactivity and cross-protectivity of isoforms.yersinia pestis caf1 is a multifunctional protein responsible for antiphagocytic activity and is a key protective antigen. it is generally conserved between globally distributed y. pestis strains, but y. pestis subsp. microtus biovar caucasica strains circulating within populations of common voles in georgia and armenia were reported to carry a single substitution of alanine to serine. we investigated polymorphism of the caf1 sequences among other y. pestis subsp. microtus strains, which have a ...201627606595
assessment of live plague vaccine candidates.since its creation in the early twentieth century, live plague vaccine ev has been successfully applied to millions of people without severe complications. this vaccine has been proven to elicit protection against both bubonic and pneumonic plague, and it is still in use in populations at risk mainly in the countries of the former soviet union. despite extensive efforts in developing subunit vaccines, there is a reviving interest in creation of a precisely attenuated strain of yersinia pestis su ...201627076149
[morphofunctional evaluation of the state of cells of apud-system biomodel during anti-plague vaccine process].study reaction of cells of apud-system of lymphoid organs and intestine of guinea pigs at the stages of morpho- and immunogenesis in response to administration of yersinia pestis ev research institute of epidemiology and hygiene (rieh) line vaccine strain.201324341215
yersinia pestis biovar microtus strain 201, an avirulent strain to humans, provides protection against bubonic plague in rhesus macaques.yersinia pestis biovar microtus is considered to be a virulent to larger mammals, including guinea pigs, rabbits and humans. it may be used as live attenuated plague vaccine candidates in terms of its low virulence. however, the microtus strain's protection against plague has yet to be demonstrated in larger mammals. in this study, we evaluated the protective efficacy of the microtus strain 201 as a live attenuated plague vaccine candidate. our results show that this strain is highly attenuated ...201424225642
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