measuring the efficacy of vaccination in affording protection against plague.the relationship of f1 antibody titre to protection against plague was investigated by subjecting seropositive laboratory rats to virulent challenge and observing for survival. the passive haemagglutination (pha) test in microtitre was employed for serology. rats vaccinated with live vaccine ev76 (51f), killed u.s.p. vaccine, or f1 antigen and challenged by subcutaneous inoculation of 1 x 10(3) to 5 x 10(5)yersinia pestis survived at similar rates that, overall, equalled 6% at titres less than 1 ...1979312163
[the sensitivity of bacterial strains of yersinia pestis isolated from voles to normal human serum].the work deals with the results of the study of the viability of y. pestis strains, isolated from voles in different natural foci of plague, in human normal serum (hns) and its dependence on the assimilation of ions of exogenic iron. the cultures isolated at the transcaucasian mountain focus of infection and having no small plasmid pyp were found highly sensitive to hns. the introduction of the sources of iron, such as hemoglobin or ferritin, into the serum decreased its bactericidal effect.19921301669
prevalence of ompt among escherichia coli isolates of human origin.ompt is a protease associated with the outer membrane of escherichia coli and possesses a high degree of homology to the plasminogen activator, pla, of yersinia pestis. we show here that ompt from intact cells can indeed activate plasminogen. clinical specimens of e. coli were examined for protease activity and for the ompt gene. few isolates (12%) were found to be positive for ompt activity, whereas most (77%) carried the ompt gene and expressed the cloned protease gene. in this report we prese ...19921427004
plague and tularemia.human plague is a local or systemic flea-transmitted infection caused by yersinia pestis. it is maintained in well established enzootic foci among wild rodents. this article discusses the clinical findings in plague, diagnosis, treatment, and prevention of plague, and management of contacts of human plague cases and of exposures to epizootic plague. tularemia shares many features with plague but is widespread in animal and arthropod vector populations and essentially throughout the united states ...19912051013
[the utilization of heme iron by yersinia pestis in human blood and blood sera].y. pestis, the causative agents of plague, have been found to be incapable of using heme iron bound to haptoglobin and hemopexin complexes in human blood and blood serum, and protein components of the serum are not the factors inhibiting this process. at the same time iron of free hemoglobin can be successfully utilized by y. pestis in the systems used in this study. on the contrary, hemin not only produces any stimulating effect on the growth of y. pestis in blood serum, but leads to the death ...19902075759
interaction of lectins with yersinia pestis strains.the ability of lectins to interact with yersinia pestis strains isolated from rodent fleas and human biological fluids, obtained from different geographic areas, was examined. lectins of canavalia ensiformis, ulex europaeus, phaseolus vulgaris, and triticum vulgaris, as well as a new autochthonous lectin of swartzia pickellii of undefined specificity, were used. most of the y. pestis strains did not agglutinate with u. europaeus or c. ensiformis lectin. however, p. vulgaris lectin agglutinated s ...19902091525
[the modifying action of normal human blood serum on vaccinal ev76 and virulent 363(1/1479) strains of yersinia pestis]. 19883249590
probing the phagolysosomal environment of human macrophages with a ca2+-responsive operon fusion in yersinia pestis.several microorganisms, including yersinia sp., salmonella sp., brucella sp., mycobacterium sp. and leishmania sp., have successfully adapted to grow within macrophage phagolysosomes. infections caused by these intracellular pathogens are among the most difficult to treat. as part of an antimicrobial strategy directed at modifying the phagolysosomal environment to the disadvantage of these important pathogens, we are defining the ambient conditions within the organism-containing phagolysosome. t ...19863748170
the action of the yersinia pestis phage on the plague envelope antigen and the human erythrocytes.the activity of the yersinia pestis phage on the plague envelope antigen has been described. the purified envelope antigen was shown to possess the receptor properties. the phage caused changes of viscosity and hemagglutination properties of the antigen. the phage-treated antigen showed the additional precipitation arc in the immunoelectrophoretic investigations. the adsorption of the yersinia pestis phage on the sheep and human erythrocytes was examined. the human red cells of group b exhibited ...19853841818
studies on yersinia enterocolitica with special reference to bacterial diagnosis and occurrence in human acute enteric disease. 19694190521
[heterogenetic antigens of plague and cholera microbes, similar to antigens of human and animal tissues]. 19724623967
unusual cases of human plague in southern africa. 19734797079
[karyometric study of the reaction of cells in monolayer tissue culture of human embryo to infection with virulent bacterial strains]. 19664968845
early serological non-response in human plague infections. 19675301390
use of uv-irradiated bacteriophage t6 to kill extracellular bacteria in tissue culture infectivity assays.we have utilized 'lysis from without' mediated by uv-inactivated bacteriophage t6 to eliminate extracellular bacteria in experiments measuring the internalization, intracellular survival and replication of yersinia pestis within mouse peritoneal macrophages and of shigella flexneri within a human intestinal epithelial cell line. the technique we describe has the following characteristics: (a) bacterial killing is complete within 15 min at 37 degrees c, with a greater than 10(3)-fold reduction in ...19836338113
studies on plague in the eastern cape province of south africa.investigations were carried out in the area of a human plague outbreak in march 1982 at coega in the eastern cape province of south africa. trapping revealed that rodent populations were high owing primarily to a population increase of the four-striped mouse, rhabdomys pumilio. flea populations were low and had been declining in the eastern cape province since october 1981. the results of a serological survey from march to october 1982 showed haemagglutinating antibody to yersinia pestis in 0.35 ...19836665833
plague in brazil during two years of bacteriological and serological north-east brazil, where plague infection is endemic, bacteriological and serological methods were employed during a two-year period to determine accurately the occurrence of human infection and to define certain epidemiological features of both human and rodent infection. there were 67 confirmed cases of plague, predominantly among males and children. most of these cases occurred in two inland rural plateaux of ceara state. clustering of cases in place and time was common, as was a history o ...19816976228
serological surveillance of plague in dogs and cats, california, 1979-1991.following natural infection both cats and dogs develop antibodies to plague which can be measured for several months after infection. besides being helpful in the diagnosis of plague in domestic carnivores, the antibody titer has important implications in outbreak investigation and surveillance programs. we report the first serological survey for plague in domestic carnivores conducted in california between 1979 and 1991 in five different settings or programs. a total of 4115 dogs and 466 cats w ...19947924244
involvement of dogs in plague epidemiology in tanzania. serological observations in domestic animals in lushoto district.venous blood was collected aseptically from clinically healthy domestic dogs, goats, sheep, cats and fowl in various plague-infected villages of lushoto district, tanzania, at the time when the disease was actively prevalent in the area. flea ectoparasites were collected from the animals, processed, identified and counted. serum samples were tested for specific plague antibodies, using the passive haemagglutination technique and checked by passive haemagglutination inhibition tests. altogether 3 ...19938248751
bacterial and viral protein tyrosine phosphatases.unrestricted protein tyrosine phosphatase (ptpase) activity may play a role in pathogenesis. for instance, the virulence determinant gene, yoph, of yersinia pseudotuberculosis encodes a ptpase. the phosphatase activity of the yoph protein is essential for the pathogenesis of y. pseudotuberculosis. yersinia pestis, the bacterium which causes the bubonic plague, also contains a gene closely related to yoph. the action of yoph on host proteins appears to break down signal transduction mechanisms in ...19938305677
identification of yersinia pestis by bbl crystal enteric/nonfermenter identification system.the bbl crystal enteric/nonfermenter system (crystal) was used to test 25 archived isolates of yersinia pestis to obtain a unique biochemical profile code for y. pestis. the revised crystal system and the api 20e system were compared by using 12 clinical human isolates of y. pestis. crystal correctly identified 11 of the 12 isolates, while api correctly identified 7 of the 12 isolates.19968897192
an overview of plague in the united states and a report of investigations of two human cases in kern county, california, 1995.plague was confirmed in the united states from nine western states during 1995. evidence of yersinia pestis infection was identified in 28 species of wild or domestic mammals. thirteen of the plague positive species were wild rodents; 15 were predators/carnivores. yersinia pestis was isolated from eight species of fleas. seven confirmed cases of human plague were reported in 1995 (new mexico 3; california 2; arizona and oregon 1 each). five of the seven cases were bubonic; one was septicemic and ...19979221742
[seroepidemiologic study of human plague in madagascar].an igg anti-f1 enzyme linked immunosorbent assay (elisa) has been developed for plague diagnosis in the malagasy republic. the sensitivity of the test was 91.4% and the specificity 98.5%. this technique is cheap and the cross reaction with other infections diseases prevalent in madagascar is very limited. during the urban plague outbreak (mahajanga city, 1995), the positive predictive value and the negative predictive value were 95.2% and 97% respectively. during this outbreak, the usefulness of ...19979309233
surveillance of human yersinia enterocolitica infections in belgium: 1967-1996.between 1967 and 1996, > 18,700 strains of yersinia species, excluding yersinia pestis, were recovered in belgium from a variety of gastrointestinal and extraintestinal sites in patients. full identification and serotyping were performed by the two belgian reference laboratories. yersinia enterocolitica serogroup o:3 predominated (79.4% of strains), followed by serogroup o:9 (11.1%). the remaining 9.5% of isolates belonged to serogroups and related species generally considered nonpathogenic. acu ...19989675452
entomological and rodent surveillance of suspected plague foci in agro-environmental and feral biotopes of a few districts in maharashtra and gujarat states of india.studies carried out on entomological and rodent surveillance in agroclimatic and feral biotopes of five districts of maharashtra and two districts of gujarat revealed that the terrain features of the seven districts surveyed were conducive to wild rodent species, tatera indica, a natural reservoir of plague and vector flea species, xenopsylla cheopis. a total of 214 tatera indica and three bandicoota bengalensis were collected from burrows by the digging method and 89 rat fleas were retrieved. t ...19979789784
expression of plasminogen activator pla of yersinia pestis enhances bacterial attachment to the mammalian extracellular matrix.the effect of the plasminogen activator pla of yersinia pestis on the adhesiveness of bacteria to the mammalian extracellular matrix was determined. y. pestis kim d27 harbors the 9.5-kb plasmid ppcp1, encoding pla and pesticin; the strain efficiently adhered to the reconstituted basement membrane preparation matrigel, to the extracellular matrix prepared from human lung nci-h292 epithelial cells, as well as to immobilized laminin. the isogenic strain y. pestis kim d34 lacking ppcp1 exhibited low ...19989826351
a complex composed of sycn and yscb functions as a specific chaperone for yopn in yersinia pestis.human pathogenic yersinia resist host defences, in part through the expression and delivery of a set of plasmid-encoded virulence proteins termed yops. a number of these yops are exported from the bacteria directly into the cytoplasm of their eukaryotic host's cells upon contact with these cells. the secreted yopn protein (also known as lcre) is required to block yop secretion in the presence of calcium in vitro or before contact with a eukaryotic cell in vivo. in this study, we characterize the ...199810094626
cellulose acetate as solid phase in elisa for plague.antigen from yersinia pestis was adsorbed on cellulose acetate discs (0.5 cm of diameter) which were obtained from dialysis membrane by using a paper punch. elisa for human plague diagnosis was carried out employing this matrix and was capable to detect amount of 1.3 microg of antigen, 3,200 times diluted positive serum using human anti-igg conjugate diluted 1:4,000. no relevant antigen lixiviation from the cellulose acetate was observed even after washing the discs 15 times. the discs were impr ...200010656712
identification of sequences encoding the detoxification metalloisomerase glyoxalase i in microbial genomes from several pathogenic organisms.the ubiquitous glyoxalase system, which is composed of two enzymes, removes cellular cytotoxic methylglyoxal (mg). in an effort to identify critical residues conserved in the evolution of the first enzyme in this system, glyoxalase i (glxi), as well as the structural implications of sequence alterations in this enzyme, a search of the national center for biotechnology information (ncbi) database of unfinished genomes was undertaken. eleven putative glxi sequences from pathogenic organisms were i ...200010824093
identification of yersinia pestis as the causative organism of plague in india as determined by 16s rdna sequencing and rapd-based genomic fingerprinting.eighteen isolates of bacteria obtained from the sputum of pneumonic plague patients and from the liver and spleen of rodents from the plague-affected areas of india during 1994-1995 when analyzed by 16s rdna analysis clearly demonstrated that all 18 isolates exhibit an average similarity of 98.5% with the genus yersinia and 99.1% with yersinia pestis, thus identifying the isolates as y. pestis. the isolates from the human plague patients were found to be genetically more homogeneous compared to ...200010930746
sequence analysis of the aminoacylase-1 family. a new proposed signature for metalloexopeptidases.the amino acid sequence analysis of the human and porcine aminoacylases-1, the carboxypeptidase s precursor from saccharomyces cerevisiae, the succinyl-diaminopimelate desuccinylase from escherichia coli, haemophilus influenzae and corynebacterium glutamicum, the acetylornithine deacetylase from escherichia coli and dictyostelium discoideum and the carboxypeptidase g(2) precursor from pseudomonas strain, using the basic local alignment search tool (blast) and the position-specific iterated blast ...200111250542
genome sequence of yersinia pestis, the causative agent of plague.the gram-negative bacterium yersinia pestis is the causative agent of the systemic invasive infectious disease classically referred to as plague, and has been responsible for three human pandemics: the justinian plague (sixth to eighth centuries), the black death (fourteenth to nineteenth centuries) and modern plague (nineteenth century to the present day). the recent identification of strains resistant to multiple drugs and the potential use of y. pestis as an agent of biological warfare mean t ...200111586360
bacterial plasminogen activators and receptors.invasive bacterial pathogens intervene at various stages and by various mechanisms with the mammalian plasminogen/plasmin system. a vast number of pathogens express plasmin(ogen) receptors that immobilize plasmin(ogen) on the bacterial surface, an event that enhances activation of plasminogen by mammalian plasminogen activators. bacteria also influence secretion of plasminogen activators and their inhibitors from mammalian cells. the prokaryotic plasminogen activators streptokinase and staphylok ...200111742690
studying genomes through the aeons: protein families, pseudogenes and proteome evolution.protein families can be used to understand many aspects of genomes, both their "live" and their "dead" parts (i.e. genes and pseudogenes). surveys of genomes have revealed that, in every organism, there are always a few large families and many small ones, with the overall distribution following a power-law. this commonality is equally true for both genes and pseudogenes, and exists despite the fact that the specific families that are enlarged differ greatly between organisms. furthermore, becaus ...200212083509
pathogenic yersinia enterocolitica strains increase the outer membrane permeability in response to environmental stimuli by modulating lipopolysaccharide fluidity and lipid a structure.pathogenic biotypes of yersinia enterocolitica (serotypes o:3, o:8, o:9, and o:13), but not environmental biotypes (serotypes o:5, o:6, o:7,8, and o:7,8,13,19), increased their permeability to hydrophobic probes when they were grown at ph 5.5 or in egta-supplemented (ca(2+)-restricted) media at 37 degrees c. a similar observation was also made when representative strains of serotypes o:8 and o:5 were tested after brief contact with human monocytes. the increase in permeability was independent of ...200312654821
[observations on the 1348 plague epidemic. measures taken to combat its tragic effects and avoid epidemic recrudescence].when the "black death" swept through europe from southern france in 1348, in the short space of two years the europeans were hit by one of the most serious epidemics ever recorded in human history. yersinia pestis reached europe by sea, its contamination propagated by the genoese ships coming from the crimean port of jaffa. for the first time the world experienced microbiological unification: east and west were equally involved in the tragedy that spread, and no town remained unscathed during th ...200312719673
plague pneumonia disease caused by yersinia pestis.plague is a zoonotic infection caused by yersina pesits, a pleomorphic, gram-negative non-spore-forming coccobacillus that is more accurately classified as a subspecies of y pseudotuberculosis. animal reservoirs include rodents, rabbits, and occasionally larger animals. cats become ill and have spread pneumonic disease to man. dogs may be a significant sentinel animal as well as a reservoir, although do not usually become ill. flea bites commonly spread disease to man. person to person spread ha ...19979097371
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
peers rally in support of accused scientist. 200312955104
[lysis of fibrin of human and animal blood by b. pestis]. 196013723596
[on common antigen properties between the human blood group abo and the pathogen of diseases dangerous for the community. preliminary report]. 196013854323
the usual suspects.any scientist will think twice before reporting any discrepancy or possible theft of biohazardous material to either his or her institution or to the government.200314519188
yersinia pestis infection in three dogs.yersinia pestis infection was diagnosed in 3 dogs. clinical signs included lethargy (3 dogs), pyrexia (2 dogs), and a purulent skin lesion in the cervical region (2 dogs). yersinia pestis infection is a potentially fatal zoonotic disease of human beings. human cases have resulted from contact with infected domestic cats; however, the risk of human infection from contact with infected domestic dogs is unknown. dogs frequently are exposed to y pestis in areas in which there are plague epizootics; ...19957628931
atypical plague bacilli isolated from rodents, fleas, and man. 1978637172
recent emergence of new variants of yersinia pestis in madagascar.yersinia pestis, the causative agent of plague, has been responsible for at least three pandemics. during the last pandemic, which started in hong kong in 1894, the microorganism colonized new, previously unscathed geographical areas where it has become well established. the aim of this longitudinal study was to investigate the genetic stability of y. pestis strains introduced into a new environment just under a century ago and to follow the epidemiology of any new genetic variant detected. in t ...19979350742
[phosphoinositide metabolism in endothelial cells of the human umbilical vein exposed to y. pestis toxin]. 19948012018
yersinia pestis: still a plague in the 21st century.yersinia pestis, the causative agent of plague, is an aerobic, non-motile, gram-negative bacillus belonging to the family enterobacteriacea. it is a zoonotic infection transmitted to humans via the bite of a flea. three clinical forms of human plague exist: bubonic, pneumonic, and septicemic. many important virulence factors associated with this organism are responsible for its extreme pathogenicity and high mortality rates. the bubonic form of plague is usually not transmitted human to human bu ...200415011977
bubonic plague from exposure to a rabbit: a documented case, and a review of rabbit-associated plague cases in the united states.a 62-year-old woman developed bubonic plague with an epitrochlear bubo one to two days after skinning two cottontail rabbits. the implicated rabbits were later recovered from the patient's freezer, and yersinia pestis was isolated from marrows of both rabbits. although human plague cases in the united states have occasionally been traced to exposure to wild rabbits, this is the first documentation of plague infection in the actual rabbits to which the patient was exposed. all reported cases of r ...1976937344
the use of live attenuated bacteria as a delivery system for heterologous attenuated mutants of several pathogenic bacteria have been exploited as potential vaccine vectors for heterologous antigen delivery by the mucosal route. such live vectors offer the advantage of potential delivery in a single oral, intranasal or inhalational dose, stimulating both systemic and mucosal immune responses. over the years, a range of strategies have been developed to allow controlled and stable delivery of antigens and improved immunogenicity where required. most of these appro ...200315203915
distinct classes of glyoxalase i: metal specificity of the yersinia pestis, pseudomonas aeruginosa and neisseria meningitidis enzymes.the metalloisomerase glyoxalase i (glxi) catalyses the conversion of methylglyoxal-glutathione hemithioacetal and related derivatives into the corresponding thioesters. in contrast with the previously characterized glxi enzymes of homo sapiens, pseudomonas putida and saccharomyces cerevisiae, we recently determined that escherichia coli glxi surprisingly did not display zn2+-activation, but instead exhibited maximal activity with ni2+. to investigate whether non-zn2+ activation defines a distinc ...200415270717
spatial analysis of yersinia pestis and bartonella vinsonii subsp. berkhoffii seroprevalence in california coyotes (canis latrans).zoonotic transmission of sylvatic plague caused by yersinia pestis occurs in california, usa. human infections with various bartonella species have been reported recently. coyotes (canis latrans) are ubiquitous throughout california and can become infected with both bacterial agents, making the species useful for surveillance purposes. this study examined the geographic distribution of 863 coyotes tested for y. pestis and bartonella vinsonii subsp. berkhoffii serologic status to gain insight int ...200312507856
modeling of seb-induced host gene expression to correlate in vitro to in vivo responses.detection of exposure to biological threat agents has relied on ever more sensitive methods for pathogen identification, but that usually requires pathogen proliferation to dangerous, near untreatable levels. recent events have demonstrated that assessing exposure to a biological threat agent well in advance of onset of illness or at various stages post-exposure is invaluable among the diagnostic options. there is an urgent need for better diagnostic tools that will be sensitive, rapid, and unam ...200415522586
microevolution and history of the plague bacillus, yersinia pestis.the association of historical plague pandemics with yersinia pestis remains controversial, partly because the evolutionary history of this largely monomorphic bacterium was unknown. the microevolution of y. pestis was therefore investigated by three different multilocus molecular methods, targeting genomewide synonymous snps, variation in number of tandem repeats, and insertion of is100 insertion elements. eight populations were recognized by the three methods, and we propose an evolutionary tre ...200415598742
from the recent lessons of the malagasy foci towards a global understanding of the factors involved in plague of human cases of plague after decades of silence does not necessarily mean that plague foci are re-emerging. most often, yersinia pestis bacteria have been maintained and circulating at low levels in the rodent populations. it seems therefore more appropriate to speak in terms of expansion or regression phases for sylvatic rodent plague foci and to reserve the term re-emergence for human cases. from the analysis of well-documented human plague cases in madagascar, we underline the ...200515845233
polyaniline-dacron composite as solid phase in enzyme linked immunosorbent assay for yersinia pestis antibody detection.polyaniline (pani) was chemically synthesized on a dacron disk surface and an antigen (f1 fraction) obtained from yersinia pestis was covalently fixed onto this composite via glutaraldehyde. the enzyme linked immunosorbent assay (elisa) or rapid elisa procedure detected immunoglobulin g (igg) anti-f1 fraction in human serum employing this derivative. the appropriate conditions for carrying out the test were established as an antigen concentration of 2 microg/pani-dacron disk, peroxidase labeled ...200111340597
is1414, an escherichia coli insertion sequence with a heat-stable enterotoxin gene embedded in a transposase-like gene.enteroaggregative escherichia coli (eaec) heat-stable enterotoxin 1 (east1) was originally discovered in eaec but has also been associated with enterotoxigenic e. coli (etec). multiple genomic restriction fragments from each of three etec strains of human origin showed homology with an east1 gene probe. a single hybridizing fragment was detected on the plasmid of etec strain 27d that also encodes heat-stable enterotoxin ib and colonization factor antigen i. we isolated and characterized this fra ...200010992475
recognizing the pseudogenes in bacterial genomes.pseudogenes are now known to be a regular feature of bacterial genomes and are found in particularly high numbers within the genomes of recently emerged bacterial pathogens. as most pseudogenes are recognized by sequence alignments, we use newly available genomic sequences to identify the pseudogenes in 11 genomes from 4 bacterial genera, each of which contains at least 1 human pathogen. the numbers of pseudogenes range from 27 in staphylococcus aureus mw2 to 337 in yersinia pestis co92 (e.g. 1- ...200515933207
incidence of plague associated with increased winter-spring precipitation in new mexico.plague occurs episodically in many parts of the world, and some outbreaks appear to be related to increased abundance of rodents and other mammals that serve as hosts for vector fleas. climate dynamics may influence the abundance of both fleas and mammals, thereby having an indirect effect on human plague incidence. an understanding of the relationship between climate and plague could be useful in predicting periods of increased risk of plague transmission. in this study, we used correlation ana ...199910586917
[ofloxacin efficacy in the prophylaxis and treatment of experimental plague due to antigen complete and defective strains of the pathogen].strains of the plague microbe, antigen complete and defective by fraction i and mouse toxin had the same in vitro susceptibility to ofloxacin (mic 0.08 mg/l). the drug was superior in its activity to pefloxacin and especially nalidixic acid. in the experiments with albino mice (prophylaxis, 5 days) the ofloxacin efficacy was lower when the infection was due to the plague microbe strains deprived of the ability to produce fraction i and mouse toxin, evident from a statistically significant increa ...200216127904
bubonic plague: a molecular genetic case history of the emergence of an infectious disease.yersinia pestis, the bacterial agent of bubonic plague, is transmitted primarily by fleas and has been responsible for devastating epidemics throughout history. y. pseudotuberculosis is a food- and water-borne pathogen that causes a much more benign enteric disease in humans. despite these profoundly different pathogenesis strategies, the two bacteria are very closely related phylogenetically. thus, identifying the specific genetic differences between them should provide an instructive case stud ...19979351703
identification of an abc transporter required for iron acquisition and virulence in mycobacterium tuberculosis.iron availability affects the course of tuberculosis infection, and the ability to acquire this metal is known to be essential for replication of mycobacterium tuberculosis in human macrophages. m. tuberculosis overcomes iron deficiency by producing siderophores. the relevance of siderophore synthesis for iron acquisition by m. tuberculosis has been demonstrated, but the molecules involved in iron uptake are currently unknown. we have identified two genes (irta and irtb) encoding an abc transpor ...200616385031
analysis of genetic algorithm for rule-set production (garp) modeling approach for predicting distributions of fleas implicated as vectors of plague, yersinia pestis, in california.more than 20 species of fleas in california are implicated as potential vectors of yersinia pestis. extremely limited spatial data exist for plague vectors-a key component to understanding where the greatest risks for human, domestic animal, and wildlife health exist. this study increases the spatial data available for 13 potential plague vectors by using the ecological niche modeling system genetic algorithm for rule-set production (garp) to predict their respective distributions. because the a ...200616506453
[fleas and diseases transmissible to man].fleas are wingless insects that parasitize mammals and more rarely birds. they are able to jump and may bite people. adult fleas are hematophagous. the impact of fleas on public health is related to their ability to act as vectors for transmission of infectious agents during blood meals. the purpose of this article is to describe fleas and the diseases that they transmit to humans. special focus is placed on epidemiological aspects.200616615611
serodiagnosis of human plague by a combination of immunomagnetic separation and flow cytometry.plague is a severe, highly communicable bacterial disease caused by yersinia pestis. it is still endemic in more than 20 countries worldwide. although known as a devastating disease for centuries, laboratory confirmation of clinical suspected cases is still problematic. no standardized and internationally approved test system is commercially available. the aim of this study was the introduction and evaluation of a combination of immunomagnetic separation and flow cytometry for the serodiagnosis ...200312766970
[a comparative analysis of molecular-genetic peculiarities of the genomes of cholera, plague and anthrax agents and their evolutional transformations].cholera, plague, and anthrax, the diseases that have accounted for millions of human victims, still endanger the entire mankind by possible development of epidemic outbreaks due to their spread or application as bioterrorist agents. generalized results of research into the genomic features of the vibrio cholerae, yersinia pestis, and bacillus anthracis are discussed. despite different frequencies of evolutional transformations occurring in their genomes, that are likely to be associated with div ...200616755997
impact of plague on human history. 200616762738
plague dynamics are driven by climate variation.the bacterium yersinia pestis causes bubonic plague. in central asia, where human plague is still reported regularly, the bacterium is common in natural populations of great gerbils. by using field data from 1949-1995 and previously undescribed statistical techniques, we show that y. pestis prevalence in gerbils increases with warmer springs and wetter summers: a 1 degrees c increase in spring is predicted to lead to a >50% increase in prevalence. climatic conditions favoring plague apparently e ...200616924109
the pla surface protease/adhesin of yersinia pestis mediates bacterial invasion into human endothelial cells.the plasminogen activator pla of yersinia pestis belongs to the omptin family of enterobacterial surface proteases and is responsible for the highly efficient invasion of the plague bacterium from the subcutaneous infection site into the circulation. y. pestis has been reported to invade human epithelial cells. here, we investigated the role of pla in bacterial invasion into human endothelial cells. expression of pla in recombinant escherichia coli xl1(pmrk1) enhanced bacterial invasion into ecv ...200111522299
microarray expression profiling of yersinia pestis in response to chloramphenicol.plague is a deadly disease caused by yersinia pestis. human plague can be effectively controlled by timely antibiotic administration, chloramphenicol being a drug of choice. in this study, a dna microarray was used to investigate the gene expression profile of y. pestis in response to chloramphenicol. seven hundred and fifty-five genes were differentially expressed on chloramphenicol treatment: 364 genes were up-regulated and 391 were down-regulated. in addition to a large number of genes encodi ...200616958847
vaccination against bubonic and pneumonic plague.yersinia pestis is the etiological agent of bubonic and pneumonic plague, diseases which have caused over 200 milllion human deaths in the past. plague still occurs throughout the world today, though for reasons that are not fully understood pandemics of disease do not develop from these outbreaks. antibiotic treatment of bubonic plague is usually effective, but pneumonic plague is difficult to treat and even with antibiotic therapy death often results. a killed whole cell plague vaccine has bee ...200111457543
treatment of plague: promising alternatives to antibiotics.plague still poses a significant threat to human health, and interest has been renewed recently in the possible use of yersinia pestis as a biological weapon by terrorists. the septicaemic and pneumonic forms are always lethal if untreated. attempts to treat this deadly disease date back to the era of global pandemics, when various methods were explored. the successful isolation of the plague pathogen led to the beginning of more scientific approaches to the treatment and cure of plague. this su ...200617030904
[the discovery by paul-louis simond of the role of the flea in the transmission of the plague].after yersin's two fundamental discoveries of the plague bacillus and of the rat's role in its propagation, no one had sought to solve the riddle of how the bacillus itself spread and how it contaminated man. p. l. simond was the first to realise that manipulating a rat that had recently died could be extremely dangerous whereas after a time lapse of several hours the same dead rat presented no risks to man. he was also the first to detect an insect bite as being responsible for the lesions he h ...199911000944
cases of cat-associated human plague in the western us, 1977-1998.exposure to cats infected with yersinia pestis is a recently recognized risk for human plague in the us. twenty-three cases of cat-associated human plague (5 of which were fatal) occurred in 8 western states from 1977 through 1998, which represent 7.7% of the total 297 cases reported in that period. bites, scratches, or other contact with infectious materials while handling infected cats resulted in 17 cases of bubonic plague, 1 case of primary septicemic plague, and 5 cases of primary pneumonic ...200010852811
pathobiology and management of laboratory rodents administered cdc category a agents.the centers for disease control and prevention category a infectious agents include bacillus anthracis (anthrax), clostridium botulinum toxin (botulism), yersinia pestis (plague), variola major virus (smallpox), francisella tularensis (tularemia), and the filoviruses and arenaviruses that induce viral hemorrhagic fevers. these agents are regarded as having the greatest potential for adverse impact on public health and therefore are a focus of renewed attention in infectious disease research. fre ...200717348288
prevention of immune cell apoptosis as potential therapeutic strategy for severe infections.some labile cell types whose numbers are normally controlled through programmed cell death are subject to markedly increased destruction during some severe infections. lymphocytes, in particular, undergo massive and apparently unregulated apoptosis in human patients and laboratory animals with sepsis, potentially playing a major role in the severe immunosuppression that characterizes the terminal phase of fatal illness. extensive lymphocyte apoptosis has also occurred in humans and animals infec ...200717479879
[pulmonic plague].one hundred years after yersin discovered yersinia pestis during the plague epidemic in hong kong in 1894, human plague still has not been eliminated. the epidemic in 1994 in india, a country where no cases had been observed since 1996, raised great concern. plague is an epizootic bacterial infection caused by a gram negative coccobacillus, y. pestis, transmitted by the bite of infected fleas. bubonic plague is the most common form. other clinical presentations include asymptomatic plague, abort ...199810100351
herpesvirus latency confers symbiotic protection from bacterial infection.all humans become infected with multiple herpesviruses during childhood. after clearance of acute infection, herpesviruses enter a dormant state known as latency. latency persists for the life of the host and is presumed to be parasitic, as it leaves the individual at risk for subsequent viral reactivation and disease. here we show that herpesvirus latency also confers a surprising benefit to the host. mice latently infected with either murine gammaherpesvirus 68 or murine cytomegalovirus, which ...200717507983
residence-linked human plague in new mexico: a habitat-suitability model.yersinia pestis, the causative agent of plague, has been detected in fleas and mammals throughout the western united states. this highly virulent infection is rare in humans, surveillance of the disease is expensive, and it often was assumed that risk of exposure to y. pestis is high in most of the western united states. for these reasons, some local health departments in these plague-affected regions have hesitated to undertake surveillance and other prevention activities. to aid in targeting l ...200717620642
how the structural gene products of yersinia pestis relate to virulence.bubonic plague is the most devastating acute infectious disease known to man. the causative agent, yersinia pestis, is now more firmly entrenched in sylvatic reservoirs throughout the world than at any time in the past. consequently, the organism increasingly causes casual human disease and is readily available for use as a bioweapon. recent attempts to understand the severe nature of plague have focused upon its very recent divergence from yersinia pseudotuberculosis, an etiological instrument ...200717683274
the importance of the rcs phosphorelay in the survival and pathogenesis of the enteropathogenic yersiniae.the human-pathogenic yersiniae represent an ideal species group to study the evolution of highly virulent bacteria, with yersinia pestis having emerged from the enteropathogen y. pseudotuberculosis an estimated 20 000 years ago. sequence data reveal that the y. pestis genome is in the early stages of decay and contains hundreds of non-functioning pseudogenes, some of which may be important in the enteric lifestyle of y. pseudotuberculosis. bioinformatic analysis of pseudogenes from seven y. pest ...200818375804
[quarantine infectious diseases and sanitary control of territories in modern conditions]. 200818376467
dog-associated risk factors for human plague.plague is a rare but often fatal zoonosis endemic to the western united states. previous studies have identified contact with pets as a potential risk factor for infection. we conducted a matched case-control study to better define the risks associated with pets at both the household and individual levels. using a written questionnaire, we surveyed nine surviving plague patients, 12 household members of these patients, and 30 age- and neighbourhood-matched controls about household and individual ...200818489541
targeting of the yersinia pestis yopm protein into hela cells and intracellular trafficking to the nucleus.the yopm virulence protein of yersinia pestis has been described as binding human alpha-thrombin and inhibiting thrombin-induced platelet aggregation in vitro. however, recent studies have shown that a yopm-cyaa fusion protein could be targeted vectorially into eukaryotic cells through the yersinia type iii secretion system. in this study, our objective was to characterize yopm's fate in more detail. we followed yopm in the culture medium and inside infected hela cells. we confirmed that the nat ...19989988481
insight into microevolution of yersinia pestis by clustered regularly interspaced short palindromic repeats.yersinia pestis, the pathogen of plague, has greatly influenced human history on a global scale. clustered regularly interspaced short palindromic repeat (crispr), an element participating in immunity against phages' invasion, is composed of short repeated sequences separated by unique spacers and provides the basis of the spoligotyping technology. in the present research, three crispr loci were analyzed in 125 strains of y. pestis from 26 natural plague foci of china, the former soviet union an ...200818612419
[interaction of s- and r-lipopolysaccharides of francisella tularensis with lypopolysaccharide-binding protein of human serum].investigation of ability of francisella tularensis s- and r-lypopolysaccharide (lps) preparations as well as the live bacteria with different chemotypes to interact with human lypopolysaccharide-binding protein (lbp) was carried out. it was found that lps preparations derived from virulent(s-lps) or isogenic avirulent mutant (r-lps) strains of f. tularensis had markedly lower affinity to lbp as compared with typical s-lps of salmonella abortus and r-lps of yersinia pestis. it was shown that r-lp ...200818819401
aurintricarboxylic acid blocks in vitro and in vivo activity of yoph, an essential virulent factor of yersinia pestis, the agent of plague.yersinia are causative agents in human diseases ranging from gastrointestinal syndromes to bubonic plague. there is increasing risk of misuse of infectious agents, such as yersinia pestis, as weapons of terror as well as instruments of warfare for mass destruction. yoph is an essential virulence factor whose protein-tyrosine phosphatase (ptp) activity is required for yersinia pathogenicity. consequently, there is considerable interest in developing potent and selective yoph inhibitors as novel a ...200312888560
recombinant v antigen protects mice against pneumonic and bubonic plague caused by f1-capsule-positive and -negative strains of yersinia pestis.the purified recombinant v antigen from yersinia pestis, expressed in escherichia coli and adsorbed to aluminum hydroxide, an adjuvant approved for human use, was used to immunize outbred hsd:nd4 mice subcutaneously. immunization protected mice from lethal bubonic and pneumonic plague caused by co92, a wild-type f1+ strain, or by the isogenic f1- strain c12. this work demonstrates that a subunit plague vaccine formulated for human use provides significant protection against bubonic plague caused ...19968890210
identification of novel virulence-associated genes via genome analysis of hypothetical genes.the sequencing of bacterial genomes has opened new perspectives for identification of targets for treatment of infectious diseases. we have identified a set of novel virulence-associated genes (vag genes) by comparing the genome sequences of six human pathogens that are known to cause persistent or chronic infections in humans: yersinia pestis, neisseria gonorrhoeae, helicobacter pylori, borrelia burgdorferi, streptococcus pneumoniae, and treponema pallidum. this comparison was limited to genes ...200414977936
[modulating effect of serotonin on the development of human leukocytes apoptosis induced by yersinia].effect of biogenic amine serotonin on the development of human blood leukocytes during interaction with species from yersinia genus (y. pestis ev, y. pseudotuberculosis serovars i and iv, y. enterocolitica serovars 09 and 03) was studied in model system in vitro using flow cytofluorometry. serotonin in concentration 10(-5) m had differently marked effects on yersinia spp.-induced apoptosis of leukocytes. pattern of the observed changes depended from species and serovar of yersinia. serotonin inh ...200819186545
characterization of new substrates targeted by yersinia tyrosine phosphatase yoph.yoph is an exceptionally active tyrosine phosphatase that is essential for virulence of yersinia pestis, the bacterium causing plague. yoph breaks down signal transduction mechanisms in immune cells and inhibits the immune response. only a few substrates for yoph have been characterized so far, for instance p130cas and fyb, but in view of yoph potency and the great number of proteins involved in signalling pathways it is quite likely that more proteins are substrates of this phosphatase. in this ...200919221593
development and evaluation of two simple, rapid immunochromatographic tests for the detection of yersinia pestis antibodies in humans and for plague diagnosis and surveillance are not always available and affordable in most of the countries affected by the disease. yersinia pestis isolation for confirmation is time-consuming and difficult to perform under field conditions. serologic tests like elisa require specific equipments not always available in developing countries. in addition to the existing rapid test for antigen detection, a rapid serodiagnostic assay may be useful for plague control.200919399164
tripeptide inhibitors of yersinia protein-tyrosine phosphatase.the protein-tyrosine phosphatase (ptp) 'yoph' is a virulence factor of yersinia pestis, the causative agent of plague. potential use of yersinia as a bioterrorism agent renders yoph inhibitors of therapeutic importance. previously, we had examined the inhibitory potencies of a variety of phosphotyrosyl (ptyr) mimetics against the human ptp1b enzyme by displaying them in the egfr-derived hexapeptide sequence, 'ac-asp-ala-asp-glu-xxx-leu-amide', where xxx=ptyr mimetic. the poor inhibitory potencie ...200312852970
d27-plpxl, an avirulent strain of yersinia pestis, primes t cells that protect against pneumonic plague.vaccinating with live, conditionally attenuated, pigmentation (pgm)-deficient yersinia pestis primes t cells that protect mice against pneumonic plague. however, pgm-deficient strains are not considered safe for human use because they retain substantial virulence in animal models. y. pestis strains engineered to express escherichia coli lpxl are avirulent owing to constitutive production of lipopolysaccharide with increased toll-like receptor 4-activating ability. we generated an lpxl-expressing ...200919620344
typing methods for the plague pathogen, yersinia pestis.phenotypic and genotypic methodologies have been used to differentiate the etiological agent of plague, yersinia pestis. historically, phenotypic methods were used to place isolates into one of three biovars based on nitrate reduction and glycerol fermentation. classification of y. pestis into genetic subtypes is problematic due to the relative monomorphic nature of the pathogen. resolution into groups is dependent on the number and types of loci used in the analysis. the last 5-10 years of rese ...200919714987
a novel semiquantitative fluorescence-based multiplex polymerase chain reaction assay for rapid simultaneous detection of bacterial and parasitic pathogens from blood.a multiplex polymerase chain reaction assay was developed for the rapid simultaneous detection of category a select bacterial agents (bacillus anthracis and yersinia pestis) and parasitic pathogens (leishmania species) in blood using the cepheid smart cycler platform. b. anthracis (sterne) and yersinia. pseudotuberculosis were used in the assay for optimization for b. anthracis and y. pestis, respectively. the specificity of the target amplicons [protective antigen gene of b. anthracis and rrna ...200515858151
plague vaccines and the molecular basis of immunity against yersinia pestis.yersinia pestis is the causative agent of bubonic and pneumonic plague, human diseases with high mortality. due to the microbe's ability to spread rapidly, plague epidemics present a serious public health threat. a search for prophylactic measures was initially based on historical reports of bubonic plague survivors and their apparent immunity. due to safety and efficacy concerns, killed whole-cell preparations or live-attenuated plague vaccines are no longer considered in the united states. vac ...200919786842
clinical and pathologic features of cynomolgus macaques (macaca fascicularis) infected with aerosolized yersinia pestis.since the anthrax attacks of 2001, the emphasis on developing animal models of aerosolized select agent pathogens has increased. many scientists believe that nonhuman primate models are the most appropriate to evaluate pulmonary response to, vaccines for, and treatments for select agents such as yersinia pestis (y. pestis), the causative agent of plague. a recent symposium concluded that the cynomolgus macaque (macaca fascicularis) plague model should be characterized more fully. to date, a well ...200819793459
enteroaggregative escherichia coli an emergent pathogen with different virulence properties.enteroaggregative escherichia coli (eaec) is an emergent bacterial pathogen. the first studies in developing countries with eaec strains, showed that this bacterium was associated with persistent diarrhea. however, new studies showed that eaec may be associated also with acute diarrhea, with both nosocomial and community outbreaks worldwide, and as an important pathogen of diarrheal disease in human immunodeficiency virus-infected adults. eaec strains are recognized by their characteristic aggre ...200517061538
blacmy-2-positive inca/c plasmids from escherichia coli and salmonella enterica are a distinct component of a larger lineage of plasmids.large multidrug resistance plasmids of the a/c incompatibility complex (inca/c) have been found in a diverse group of gram-negative commensal and pathogenic bacteria. we present three completed sequences from inca/c plasmids that originated from escherichia coli (cattle) and salmonella enterica serovar newport (human) and that carry the cephamycinase gene blacmy-2. these large plasmids (148 to 166 kbp) share extensive sequence identity and synteny. the most divergent plasmid, peh4h, has lost sev ...201019949054
bubonic plague: a metapopulation model of a zoonosis.bubonic plague (yersinia pestis) is generally thought of as a historical disease; however, it is still responsible for around 1000-3000 deaths each year worldwide. this paper expands the analysis of a model for bubonic plague that encompasses the disease dynamics in rat, flea and human populations. some key variables of the deterministic model, including the force of infection to humans, are shown to be robust to changes in the basic parameters, although variation in the flea searching efficienc ...200011413636
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