Publications

inactivation of avirulent yersinia pestis on food and food contact surfaces by ultraviolet light and freezing.	yersinia pestis, the causative agent of plague, can occasionally be contracted as a naso-pharyngeal or gastrointestinal illness through consumption of contaminated meat. in this study, the use of 254 nm ultraviolet light (uv-c) to inactivate a multi-isolate cocktail of avirulent y. pestis on food and food contact surfaces was investigated. when a commercial uv-c conveyor was used (5 mw/cm(2)/s) 0.5 j/cm(2) inactivated >7 log of the y. pestis cocktail on agar plates. at 0.5 j/cm(2), uv-c inactiva ...	2015	25998808
rapid detection of yersinia pestis recombinant fraction 1 capsular antigen.	yersinia pestis, an infectious bacterium that is a causative agent of plague, a disease which has been shown to be one of the most feared in history and which has caused millions of deaths. the capsule-like fraction 1 (f1) antigen expressed by y. pestis is a known specific marker for the identification of the bacteria; therefore, the detection of f1 is important for y. pestis recognition. in this study, a rapid, sensitive, and specific technique, the lateral flow assay (lfa), was successfully de ...	2015	25994256
single-nucleotide polymorphisms reveal spatial diversity among clones of yersinia pestis during plague outbreaks in colorado and the western united states.	in western north america, plague epizootics caused by yersinia pestis appear to sweep across landscapes, primarily infecting and killing rodents, especially ground squirrels and prairie dogs. during these epizootics, the risk of y. pestis transmission to humans is highest. while empirical models that include climatic conditions and densities of rodent hosts and fleas can predict when epizootics are triggered, bacterial transmission patterns across landscapes, and the scale at which y. pestis is ...	2015	25988438
[the epidemiology and etiology research of tibetan sheep plague in qinghai plateau].	to identify the epidemiology and etiology characteristics of tibetan sheep plague in qinghai plateau.	2015	25975407
circumventing y. pestis virulence by early recruitment of neutrophils to the lungs during pneumonic plague.	pneumonic plague is a fatal disease caused by yersinia pestis that is associated with a delayed immune response in the lungs. because neutrophils are the first immune cells recruited to sites of infection, we investigated the mechanisms responsible for their delayed homing to the lung. during the first 24 hr after pulmonary infection with a fully virulent y. pestis strain, no significant changes were observed in the lungs in the levels of neutrophils infiltrate, expression of adhesion molecules, ...	2015	25974210
correction: yersinia pestis activates both il-1β and il-1 receptor antagonist to modulate lung inflammation during pneumonic plague.		2015	25970482
[human plague and pneumonic plague : pathogenicity, epidemiology, clinical presentations and therapy].	yersinia pestis is a highly pathogenic gram-negative bacterium and the causative agent of human plague. in the last 1500 years and during three dreaded pandemics, millions of people became victims of justinian's plague, the black death, or modern plague. today, y. pestis is endemic in natural foci of asian, african and american countries. due to its broad dissemination in mammal species and fleas, eradication of the pathogen will not be possible in the near future. in fact, plague is currently c ...	2015	25963643
comparison of models for bubonic plague reveals unique pathogen adaptations to the dermis.	vector-borne pathogens are inoculated in the skin of mammals, most likely in the dermis. despite this, subcutaneous (s.c.) models of infection are broadly used in many fields, including yersinia pestis pathogenesis. we expand on a previous report where we implemented intradermal (i.d.) inoculations to study bacterial dissemination during bubonic plague and compare this model with an s.c.	2015	25939507
thirty-two complete genome assemblies of nine yersinia species, including y. pestis, y. pseudotuberculosis, and y. enterocolitica.	the genus yersinia includes three human pathogens, of which yersinia pestis is responsible for >2,000 illnesses each year. to aid in the development of detection assays and aid further phylogenetic elucidation, we sequenced and assembled the complete genomes of 32 strains (across 9 yersinia species).	2015	25931590
outbreak of human pneumonic plague with dog-to-human and possible human-to-human transmission--colorado, june-july 2014.	on july 8, 2014, the colorado department of public health and environment (cdphe) laboratory identified yersinia pestis, the bacterium that causes plague, in a blood specimen collected from a man (patient a) hospitalized with pneumonia. the organism had been previously misidentified as pseudomonas luteola by an automated system in the hospital laboratory. an investigation led by tri-county health department (tchd) revealed that patient a's dog had died recently with hemoptysis. three other perso ...	2015	25928467
transmission efficiency of the plague pathogen (y. pestis) by the flea, xenopsylla skrjabini, to mice and great gerbils.	plague, a zoonotic disease caused by yersinia pestis, is characterized by its ability to persist in the plague natural foci. junggar basin plague focus was recently identified in china, with rhombomys opimus (great gerbils) and xenopsylla skrjabini as the main reservoir and vector for plague. no transmission efficiency data of x. skrjabini for y. pestis is available till now.	2015	25928441
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 ...	2017	25927007
origins of yersinia pestis sensitivity to the arylomycin antibiotics and the inhibition of type i signal peptidase.	yersinia pestis is the etiologic agent of the plague. reports of y. pestis strains that are resistant to each of the currently approved first-line and prophylactic treatments point to the urgent need to develop novel antibiotics with activity against the pathogen. we previously reported that y. pestis strain kim6+, unlike most enterobacteriaceae, is susceptible to the arylomycins, a novel class of natural-product lipopeptide antibiotics that inhibit signal peptidase i (spase). in this study, we ...	2015	25896690
the role of transition metal transporters for iron, zinc, manganese, and copper in the pathogenesis of yersinia pestis.	yersinia pestis, the causative agent of bubonic, septicemic and pneumonic plague, encodes a multitude of fe transport systems. some of these are defective due to frameshift or is element insertions, while others are functional in vitro but have no established role in causing infections. indeed only 3 fe transporters (ybt, yfe and feo) have been shown to be important in at least one form of plague. the yersiniabactin (ybt) system is essential in the early dermal/lymphatic stages of bubonic plague ...	2015	25891079
[pcr-derived technology in gene identification and typing of yersinia pestis].	application of the pcr-derived technology in gene identification and genotypes of different ecotype yersinia pestis to make the high-throughput experimental results can reflect the epidemic history and compare the diversity in genome, pathogenicity, so that results from these experiments provide an important basis for clinical diagnosis, treatment and origin. but the experiment should be considered typing ability, practicality, budget and other experimental factors or conditions, because each pc ...	2015	25876503
[study of the plasmid profiles and geographical distribution of yersinia pestis in china].	to analyze the plasmid features and geographical distribution characteristics of yersinia pestis of different plague foci in china.	2015	25876488
[development and comparative evaluation of up-converting phosphor technology based lateral flow assay for rapid detection of yersinia pestis, bacillus anthracis spore and brucella spp].	to develop an up-converting phosphor technology based lateral flow (upt-lf) assay for rapid and quantitative detection of yersinia pestis, bacillus anthracis spore and brucella spp.and make the comparison with biothreat alert (bta) test strips (tetracore inc., usa).	2015	25876487
[genotyping techniques in yersinia pestis].		2015	25876486
cationic liposome-hyaluronic acid hybrid nanoparticles for intranasal vaccination with subunit antigens.	here we report the development of a new cationic liposome-hyaluronic acid (ha) hybrid nanoparticle (np) system and present our characterization of these nps as an intranasal vaccine platform using a model antigen and f1-v, a candidate recombinant antigen for yersinia pestis, the causative agent of plague. incubation of cationic liposomes composed of dotap and dope with anionic ha biopolymer led to efficient ionic complexation and formation of homogenous liposome-polymer hybrid nps, as evidenced ...	2015	25869965
pulsed-field gel electrophoresis of yersinia pestis.	yersinia pestis is a human pathogen and can cause serious disease. biosafety level 3 (bsl3) is required when handling this microorganism and all work requires a biological safety cabinet. for pulsed-field gel electrophoresis (pfge), dedicated bsl3 pfge equipment or a documented procedure that ensures that all viable bacteria are inactivated is required. all plasticware and glassware that comes into contact with the cultures should be disinfected/sterilized or disposed of in a safe manner, accord ...	2015	25862053
structural and functional characterization of tesb from yersinia pestis reveals a unique octameric arrangement of hotdog domains.	acyl-coa thioesterases catalyse the hydrolysis of the thioester bonds present within a wide range of acyl-coa substrates, releasing free coash and the corresponding fatty-acyl conjugate. the tesb-type thioesterases are members of the te4 thioesterase family, one of 25 thioesterase enzyme families characterized to date, and contain two fused hotdog domains in both prokaryote and eukaryote homologues. only two structures have been elucidated within this enzyme family, and much of the current under ...	2015	25849407
[effect of serotonin on immune competent cells of biomodels under the conditions of vaccination against plague and tularemia].	comparative evaluation of the effect of exogenic serotonin on the development of apoptosis and proliferative activity of immune system cells of biomodels in vivo and in vitro in the dynamic of immunity forming against plague and tularemia.	2015	25842950
enzootic plague foci, algeria.	in algeria, pcr sequencing of pla, glpd and rpob genes found yersinia pestis in 18/237 (8%) rodents of five species, including apodemus sylvaticus, previously undescribed as pestiferous; and disclosed three new plague foci. multiple spacer typing confirmed a new orientalis variant. rodent survey should be reinforced in this country hosting reemerging plague.	2015	25834736
host langerin (cd207) is a receptor for yersinia pestis phagocytosis and promotes dissemination.	yersinia pestis is a gram-negative bacterium that causes plague. after y. pestis overcomes the skin barrier, it encounters antigen-presenting cells (apcs), such as langerhans and dendritic cells. they transport the bacteria from the skin to the lymph nodes. however, the molecular mechanisms involved in bacterial transmission are unclear. langerhans cells (lcs) express langerin (cd207), a calcium-dependent (c-type) lectin. furthermore, y. pestis possesses exposed core oligosaccharides. in this st ...	2015	25829141
rcsab is a major repressor of yersinia biofilm development through directly acting on hmscde, hmst, and hmshfrs.	biofilm formation in flea gut is important for flea-borne transmission of yersinia pestis. there are enhancing factors (hmshfrs, hmscde, and hmst) and inhibiting one (hmsp) for yersinia pestis biofilm formation. the rcsab regulatory complex acts as a repressor of yesinia biofilm formation, and adaptive pseudogenization of rcsa promotes y. pestis to evolve the ability of biofilm formation in fleas. in this study, we constructed a set of isogenic strains of y. pestis biovar microtus, namely wt (rs ...	2015	25828910
inhibition of outer membrane proteases of the omptin family by aprotinin.	bacterial proteases are important virulence factors that inactivate host defense proteins and contribute to tissue destruction and bacterial dissemination. outer membrane proteases of the omptin family, exemplified by escherichia coli ompt, are found in some gram-negative bacteria. omptins cleave a variety of substrates at the host-pathogen interface, including plasminogen and antimicrobial peptides. multiple omptin substrates relevant to infection have been identified; nonetheless, an effective ...	2015	25824836
plague bacterium as a transformer species in prairie dogs and the grasslands of western north america.	invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. we applied the transformer species concept to the plague bacterium yersinia pestis in western north america, where the pathogen was introduced around 1900. y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (cynomys spp.) and thereby causing declines in native species abundance and diversity, includ ...	2015	25817984
[change in the habitat of yersinia pestis in the gorno-altaisk natural focus of plague].	the paper analyzes the change that occurred in the habitat of the causative agent of plague in its gorno-altaisk natural focus in 1961 to 2012. since 1961 when the plague microbe was found to come from the southern slopes of the saylyugem mountain range, which are located in mongolia, to the northern slopes situated in russia, a gradual expansion of the habitat of yersenia pestis subsp. altaica had commenced in south-eastern altai. during the considered period, the area where epizootic manifesta ...	2015	25812401
role of the phop-phoq gene regulatory system in adaptation of yersinia pestis to environmental stress in the flea digestive tract.	the yersinia pestis phopq gene regulatory system is induced during infection of the flea digestive tract and is required to produce adherent biofilm in the foregut, which greatly enhances bacterial transmission during a flea bite. to understand the in vivo context of phopq induction and to determine phop-regulated targets in the flea, we undertook whole-genome comparative transcriptional profiling of y. pestis wt and δphop strains isolated from infected fleas and from temperature-matched in vitr ...	2015	25804213
inhibition of zn(ii) binding type ia topoisomerases by organomercury compounds and hg(ii).	type ia topoisomerase activities are essential for resolving dna topological barriers via an enzyme-mediated transient single strand dna break. accumulation of topoisomerase dna cleavage product can lead to cell death or genomic rearrangement. many antibacterial and anticancer drugs act as topoisomerase poison inhibitors that form stabilized ternary complexes with the topoisomerase covalent intermediate, so it is desirable to identify such inhibitors for type ia topoisomerases. here we report th ...	2015	25798600
dermal neutrophil, macrophage and dendritic cell responses to yersinia pestis transmitted by fleas.	yersinia pestis, the causative agent of plague, is typically transmitted by the bite of an infected flea. many aspects of mammalian innate immune response early after y. pestis infection remain poorly understood. a previous study by our lab showed that neutrophils are the most prominent cell type recruited to the injection site after intradermal needle inoculation of y. pestis, suggesting that neutrophil interactions with y. pestis may be important in bubonic plague pathogenesis. in the present ...	2015	25781984
yersinia pestis activates both il-1β and il-1 receptor antagonist to modulate lung inflammation during pneumonic plague.	pneumonic plague is the most rapid and lethal form of yersinia pestis infection. increasing evidence suggests that y. pestis employs multiple levels of innate immune evasion and/or suppression to produce an early "pre-inflammatory" phase of pulmonary infection, after which the disease is highly inflammatory in the lung and 100% fatal. in this study, we show that il-1β/il-18 cytokine activation occurs early after bacteria enter the lung, and this activation eventually contributes to pulmonary inf ...	2015	25781467
host response during yersinia pestis infection of human bronchial epithelial cells involves negative regulation of autophagy and suggests a modulation of survival-related and cellular growth pathways.	yersinia pestis (yp) causes the re-emerging disease plague, and is classified by the cdc and niaid as a highest priority (category a) pathogen. currently, there is no approved human vaccine available and advances in early diagnostics and effective therapeutics are urgently needed. a deep understanding of the mechanisms of host response to yp infection can significantly advance these three areas. we employed the reverse phase protein microarray (rpma) technology to reveal the dynamic states of ei ...	2015	25762983
high-throughput, signature-tagged mutagenic approach to identify novel virulence factors of yersinia pestis co92 in a mouse model of infection.	the identification of new virulence factors in yersinia pestis and understanding their molecular mechanisms during an infection process are necessary in designing a better vaccine or to formulate an appropriate therapeutic intervention. by using a high-throughput, signature-tagged mutagenic approach, we created 5,088 mutants of y. pestis strain co92 and screened them in a mouse model of pneumonic plague at a dose equivalent to 5 50% lethal doses (ld50) of wild-type (wt) co92. from this screen, w ...	2015	25754198
mining host-pathogen protein interactions to characterize burkholderia mallei infectivity mechanisms.	burkholderia pathogenicity relies on protein virulence factors to control and promote bacterial internalization, survival, and replication within eukaryotic host cells. we recently used yeast two-hybrid (y2h) screening to identify a small set of novel burkholderia proteins that were shown to attenuate disease progression in an aerosol infection animal model using the virulent burkholderia mallei atcc 23344 strain. here, we performed an extended analysis of primarily nine b. mallei virulence fact ...	2015	25738731
concordance and discordance of sequence survey methods for molecular epidemiology.	the post-genomic era is characterized by the direct acquisition and analysis of genomic data with many applications, including the enhancement of the understanding of microbial epidemiology and pathology. however, there are a number of molecular approaches to survey pathogen diversity, and the impact of these different approaches on parameter estimation and inference are not entirely clear. we sequenced whole genomes of bacterial pathogens, burkholderia pseudomallei, yersinia pestis, and brucell ...	2015	25737810
identification of bacillus anthracis pure inhibitors with antimicrobial activity.	n(5)-carboxy-amino-imidazole ribonucleotide (n(5)-cair) mutase (pure), a bacterial enzyme in the de novo purine biosynthetic pathway, has been suggested to be a target for antimicrobial agent development. we have optimized a thermal shift method for high-throughput screening of compounds binding to bacillus anthracis pure. we used a low ionic strength buffer condition to accentuate the thermal shift stabilization induced by compound binding to bacillus anthracis pure. the compounds identified we ...	2015	25737087
helicobacter himalayensis sp. nov. isolated from gastric mucosa of marmota himalayana.	a gram-stain-negative, microaerophilic strain, 80(ys1)t, with a spiral-shaped morphology and 1-2 sheathed flagella at each end of the cells was isolated from the gastric mucosa of marmota himalayana, the animal reservoir of yersinia pestis in china, on the qinghai-tibet plateau. the strain grew at 30, 35 and 42 °c, but not at 25 °c. growth was in the form of a thinly spreading film on brain heart infusion agar containing 8 % sheep blood under microaerobic conditions. the strain did not hydrolyse ...	2015	25736414
tyrr, the regulator of aromatic amino acid metabolism, is required for mice infection of yersinia pestis.	yersinia pestis, the causative agent of plague, poses a serious health threat to rodents and human beings. tyrr is a transcriptional regulator (tyrr) that controls the metabolism of aromatic amino acids in escherichia coli. in this paper, tyrr played an important role in y. pestis virulence. inactivation of tyrr did not seem to affect the in vitro growth of this organism, but resulted in at least 10,000-fold attenuation compared with the wild-type (wt) strain upon subcutaneous infection to mice. ...	2015	25729381
distinct biological activity of lipopolysaccharides with different lipid a acylation status from mutant strains of yersinia pestis and some members of genus psychrobacter.	correlation between the chemical structure of lipid a from various gram-negative bacteria and biological activity of their lipopolysaccharide (lps) as an agonist of the innate immune receptor toll-like receptor 4 was investigated. purified lps species were quantitatively evaluated by their ability to activate the production of tumor necrosis factor (tnf) by murine bone marrow-derived macrophages in vitro. wild-type lps from plague-causing bacteria yersinia pestis was compared to lps from mutant ...	2014	25716726
[genetic basis of the variability of nitrate reduction trait in yersinia pestis strains].	the genetic basis of the varying ability to reduce nitrate in strains belonging to different biovars and subspecies of plague-causing microbe has been investigated and the inability to reduce nitrate observed in different intraspecies groups of yersinia pestis has been shown to stem from mutations in different genes involved in the expression of this trait. the absence of denitrifying activity in strains of altaica and hissarica subspecies was not due to a mutation at position 613 of the peripla ...	2014	25715468
climate-driven introduction of the black death and successive plague reintroductions into europe.	the black death, originating in asia, arrived in the mediterranean harbors of europe in 1347 ce, via the land and sea trade routes of the ancient silk road system. this epidemic marked the start of the second plague pandemic, which lasted in europe until the early 19th century. this pandemic is generally understood as the consequence of a singular introduction of yersinia pestis, after which the disease established itself in european rodents over four centuries. to locate these putative plague r ...	2015	25713390
generation of a crispr database for yersinia pseudotuberculosis complex and role of crispr-based immunity in conjugation.	the clustered regularly interspaced short palindromic repeat - crispr-associated genes (crispr-cas) system is used by bacteria and archaea against invading conjugative plasmids or bacteriophages. central to this immunity system are genomic crispr loci that contain fragments of invading dna. these are maintained as spacers in the crispr loci between direct repeats and the spacer composition in any bacterium reflects its evolutionary history. we analysed the crispr locus sequences of 335 yersinia ...	2015	25712141
effects of land use on plague (yersinia pestis) activity in rodents in tanzania.	understanding the effects of land-use change on zoonotic disease risk is a pressing global health concern. here, we compare prevalence of yersinia pestis, the etiologic agent of plague, in rodents across two land-use types-agricultural and conserved-in northern tanzania. estimated abundance of seropositive rodents nearly doubled in agricultural sites compared with conserved sites. this relationship between land-use type and abundance of seropositive rodents is likely mediated by changes in roden ...	2015	25711606
the outer membrane protease pgte of salmonella enterica interferes with the alternative complement pathway by cleaving factors b and h.	the virulence factor pgte is an outer membrane protease (omptin) of the zoonotic pathogen salmonella enterica that causes diseases ranging from gastroenteritis to severe enteric fever. it is surface exposed in bacteria that have a short-chain, i.e., rough lps, as observed e.g., in bacteria residing inside macrophages or just emerging from them. we investigated whether pgte cleaves the complement factors b (b) and h (h), key proteins controlling formation and inactivation of the complement protei ...	2015	25705210
demographic characteristics and infectious diseases of a population of american black bears in humboldt county, california.	american black bears (ursus americanus) are common, widely distributed, and broad-ranging omnivorous mammals in northern california forests. bears may be susceptible to pathogens infecting both domestic animals and humans. monitoring bear populations, particularly in changing ecosystems, is important to understanding ecological features that could affect bear population health and influence the likelihood that bears may cause adverse impacts on humans. in all, 321 bears were captured between may ...	2015	25700042
further characterization of a highly attenuated yersinia pestis co92 mutant deleted for the genes encoding braun lipoprotein and plasminogen activator protease in murine alveolar and primary human macrophages.	we recently characterized the δlpp δpla double in-frame deletion mutant of yersinia pestis co92 molecularly, biologically, and immunologically. while braun lipoprotein (lpp) activates toll-like receptor-2 to initiate an inflammatory cascade, plasminogen activator (pla) protease facilitates bacterial dissemination in the host. the δlpp δpla double mutant was highly attenuated in evoking bubonic and pneumonic plague, was rapidly cleared from mouse organs, and generated humoral and cell-mediated im ...	2015	25697665
in vivo transcriptional profiling of yersinia pestis reveals a novel bacterial mediator of pulmonary inflammation.	inhalation of yersinia pestis results in primary pneumonic plague, a highly lethal and rapidly progressing necrotizing pneumonia. the disease begins with a period of extensive bacterial replication in the absence of disease symptoms, followed by the sudden onset of inflammatory responses that ultimately prove fatal. very little is known about the bacterial and host factors that contribute to the rapid biphasic progression of pneumonic plague. in this work, we analyzed the in vivo transcription k ...	2015	25691593
adhesive properties of yapv and paralogous autotransporter proteins of yersinia pestis.	yersinia pestis is the causative agent of plague. this bacterium evolved from an ancestral enteroinvasive yersinia pseudotuberculosis strain by gene loss and acquisition of new genes, allowing it to use fleas as transmission vectors. infection frequently leads to a rapidly lethal outcome in humans, a variety of rodents, and cats. this study focuses on the y. pestis kim yapv gene and its product, recognized as an autotransporter protein by its typical sequence, outer membrane localization, and am ...	2015	25690102
differential regulation of the hmscde operon in yersinia pestis and yersinia pseudotuberculosis by the rcs phosphorelay system.	yersinia pestis, the agent of plague, forms a biofilm in its flea vector to enhance transmission. y. pestis biofilm development is positively regulated by hmst and hmsd, encoding diguanylate cyclases (dgcs) involved in synthesis of the bacterial second messenger c-di-gmp. rcsa, encoding an auxiliary protein in rcs phosphorelay, is nonfunctional in y. pestis, while in yersinia pseudotuberculosis, rcsa is functional and represses biofilms. previously we showed that rcs phosphorelay negatively regu ...	2015	25672461
the n terminus of type iii secretion needle protein yscf from yersinia pestis functions to modulate innate immune responses.	the type iii secretion system is employed by many pathogens, including the genera yersinia, shigella, pseudomonas, and salmonella, to deliver effector proteins into eukaryotic cells. the injectisome needle is formed by the polymerization of a single protein, e.g., yscf (yersinia pestis), pscf (pseudomonas aeruginosa), prgi (salmonella enterica spi-1), ssag (salmonella enterica spi-2), or mxih (shigella flexneri). in this study, we demonstrated that the n termini of some needle proteins, particul ...	2015	25644012
[yersinia pestis and plague - an update].	the plague of man is a severe, systemic bacterial infectious disease. without antibacterial therapy, the disease is associated with a high case fatality rate, ranging from 40% (bubonic plague) to nearly 100% (septicemic and pneumonic plague). the disease is caused by yersinia pestis, a non-motile, gram-negative, facultative anaerobic bacterium belonging to the family of enterobacteriaceae. in nature, y. pestis has been found in several rodent species and some other small animals such as shrews. ...	2014	25643450
hexa-acylated lps-lipid a deploys the appropriate level of fibrin to confer protection through myd88.	fibrin has been demonstrated to function protectively against pathogens in our previous studies, but we observed that a very high level of fibrin played a negative role during infection. we performed this research to address the complication.	2015	25625178
import and export of bacterial protein toxins.	the paper provides a short overview of three investigated bacterial protein toxins, colicin m (cma) of escherichia coli, pesticin (pst) of yersinia pestis and hemolysin (shlab) of serratia marcescens. cma and pst are exceptional among colicins in that they kill bacteria by degrading the murein (peptidoglycan). both are released into the medium and bind to specific receptor proteins in the outer membrane of sensitive e. coli cells. subsequently they are translocated into the periplasm by an energ ...	2015	25620353
effects of bacterial inactivation methods on downstream proteomic analysis.	inactivation of pathogenic microbial samples is often necessary for the protection of researchers and to comply with local and federal regulations. by its nature, biological inactivation causes changes to microbial samples, potentially affecting observed experimental results. while inactivation-induced damage to materials such as dna has been evaluated, the effect of various inactivation strategies on proteomic data, to our knowledge, has not been discussed. to this end, we inactivated samples o ...	2015	25620019
dissemination of a highly virulent pathogen: tracking the early events that define infection.	the series of events that occurs immediately after pathogen entrance into the body is largely speculative. key aspects of these events are pathogen dissemination and pathogen interactions with the immune response as the invader moves into deeper tissues. we sought to define major events that occur early during infection of a highly virulent pathogen. to this end, we tracked early dissemination of yersinia pestis, a highly pathogenic bacterium that causes bubonic plague in mammals. specifically, ...	2015	25611317
combinational deletion of three membrane protein-encoding genes highly attenuates yersinia pestis while retaining immunogenicity in a mouse model of pneumonic plague.	previously, we showed that deletion of genes encoding braun lipoprotein (lpp) and msbb attenuated yersinia pestis co92 in mouse and rat models of bubonic and pneumonic plague. while lpp activates toll-like receptor 2, the msbb acyltransferase modifies lipopolysaccharide. here, we deleted the ail gene (encoding the attachment-invasion locus) from wild-type (wt) strain co92 or its lpp single and δlpp δmsbb double mutants. while the δail single mutant was minimally attenuated compared to the wt bac ...	2015	25605764
yersinia adhesin a (yada)--beauty & beast.	the trimeric autotransporter adhesin yersinia adhesin a is the prototype of the type vc secretion systems. it is expressed by enteropathogenic yersinia enterocolitica and yersinia pseudotuberculosis strains, but not by yersinia pestis. a characteristic trait of yada is its modular composition and trimeric nature. yada consists of an n-terminal passenger domain which is exposed on the bacterial cell surface. the translocation of this passenger onto the surface is facilitated by a c-terminal β-bar ...	2015	25604505
comparison of eleven commercially available rapid tests for detection of bacillus anthracis, francisella tularensis and yersinia pestis.	yersinia pestis, bacillus anthracis and francisella tularensis cause serious zoonotic diseases and have the potential to cause high morbidity and mortality in humans. in case of natural outbreaks and deliberate or accidental release of these pathogens rapid detection of the bacteria is crucial for limitation of negative effects of the release. in the present study, we evaluated 11 commercially available rapid test kits for the detection of y. pestis, b. anthracis and f. tularensis in terms of se ...	2015	25598285
[plasmid types, functions of yersinia pestis and their epidemiological significance].		2014	25598268
yersiniabase: a genomic resource and analysis platform for comparative analysis of yersinia.	yersinia is a gram-negative bacteria that includes serious pathogens such as the yersinia pestis, which causes plague, yersinia pseudotuberculosis, yersinia enterocolitica. the remaining species are generally considered non-pathogenic to humans, although there is evidence that at least some of these species can cause occasional infections using distinct mechanisms from the more pathogenic species. with the advances in sequencing technologies, many genomes of yersinia have been sequenced. however ...	2015	25591325
age at vaccination may influence response to sylvatic plague vaccine (spv) in gunnison's prairie dogs (cynomys gunnisoni).	gunnison's prairie dogs (cynomys gunnisoni) have been considered at greater risk from yersinia pestis (plague) infection in the montane portion of their range compared to populations at lower elevations, possibly due to factors related to flea transmission of the bacteria or greater host susceptibility. to test the latter hypothesis and determine whether vaccination against plague with an oral sylvatic plague vaccine (spv) improved survival, we captured prairie dogs from a c. g. gunnisoni or "mo ...	2015	25589000
prevalence of the generalist flea pulex simulans on black-tailed prairie dogs (cynomys ludovicianus) in new mexico, usa: the importance of considering imperfect detection.	if a parasite is not detected during a survey, one of two explanations is possible: the parasite was truly absent or it was present but not detected. we fit occupancy models to account for imperfect detection when combing fleas (siphonaptera) from black-tailed prairie dogs (cynomys ludovicianus) during june-august 2012 in the vermejo park ranch, new mexico, usa. with the use of detection histories from combing events during monthly trapping sessions, we fit occupancy models for two flea species: ...	2015	25588009
the yersinia pestis hmscde regulatory system is essential for blockage of the oriental rat flea (xenopsylla cheopis), a classic plague vector.	the second messenger molecule cyclic diguanylate is essential for yersinia pestis biofilm formation that is important for blockage-dependent plague transmission from fleas to mammals. two diguanylate cyclases (dgcs) hmst and y3730 (hmsd) are responsible for biofilm formation in vitro and biofilm-dependent blockage in the oriental rat flea xenopsylla cheopis respectively. here, we have identified a tripartite signalling system encoded by the y3729-y3731 operon that is responsible for regulation o ...	2015	25586342
in vitro antibiotic susceptibilities of yersinia pestis determined by broth microdilution following clsi methods.	in vitro susceptibilities to 45 antibiotics were determined for 30 genetically and geographically diverse strains of yersinia pestis by the broth microdilution method at two temperatures, 28°c and 35°c, following clinical and laboratory standards institute (clsi) methods. the y. pestis strains demonstrated susceptibility to aminoglycosides, quinolones, tetracyclines, β-lactams, cephalosporins, and carbapenems. only a 1-well shift was observed for the majority of antibiotics between the two tempe ...	2015	25583720
solid-state nmr of the yersinia pestis outer membrane protein ail in lipid bilayer nanodiscs sedimented by ultracentrifugation.	solid-state nmr studies of sedimented soluble proteins has been developed recently as an attractive approach for overcoming the size limitations of solution nmr spectroscopy while bypassing the need for sample crystallization or precipitation (bertini et al. proc natl acad sci usa 108(26):10396-10399, 2011). inspired by the potential benefits of this method, we have investigated the ability to sediment lipid bilayer nanodiscs reconstituted with a membrane protein. in this study, we show that nan ...	2015	25578899
seasonal fluctuations of small mammal and flea communities in a ugandan plague focus: evidence to implicate arvicanthis niloticus and crocidura spp. as key hosts in yersinia pestis transmission.	the distribution of human plague risk is strongly associated with rainfall in the tropical plague foci of east africa, but little is known about how the plague bacterium is maintained during periods between outbreaks or whether environmental drivers trigger these outbreaks. we collected small mammals and fleas over a two year period in the west nile region of uganda to examine how the ecological community varies seasonally in a region with areas of both high and low risk of human plague cases.	2015	25573253
carrot cells: a pioneering platform for biopharmaceuticals production.	carrot (daucus carota l.) is of importance in the molecular farming field as it constitutes the first plant species approved to produce biopharmaceuticals for human use. in this review, features that make carrot an advantageous species in the molecular farming field are analyzed and a description of the developments achieved with this crop thus far is presented. a guide for genetic transformation procedures is also included. the state of the art comprises ten vaccine prototypes against measles v ...	2015	25572939
ypfφ: a filamentous phage acquired by yersinia pestis.	yersinia pestis, the plague bacillus, has an exceptional pathogenicity for humans. the plague bacillus emerged very recently (≈3,000 years ago) from the enteropathogen y. pseudotuberculosis. early after its emergence, y. pestis became infected by a filamentous phage named ypfφ. during the microevolution of the plague bacillus, the phage remained in the various lineages as an unstable extrachromosomal element. however, in the sub branch that caused the third plague pandemic, ypfφ integrated itsel ...	2014	25566217
hmsb enhances biofilm formation in yersinia pestis.	the hmshfrs operon is responsible for biosynthesis and translocation of biofilm matrix exopolysaccharide. yersinia pestis expresses the two sole diguanylate cyclases hmst and hmsd and the sole phosphodiesterase hmsp, which are specific for biosynthesis and degradation, respectively, of 3',5'-cyclic diguanosine monophosphate (c-di-gmp), a second messenger promoting exopolysaccharide production. in this work, the phenotypic assays indicates that y. pestis srna hmsb enhances the production of c-di- ...	2014	25566205
primary case of human pneumonic plague occurring in a himalayan marmot natural focus area gansu province, china.	a case of primary pneumonic plague (ppp) caused by yersinia pestis is reported. this case occurred in the largest plague area in china. the patient died after contact with a dog that had captured an infected marmot. three of 151 contacts were shown to be positive for antibody against f1 antigen by indirect hemagglutination assay, but none had clinical symptoms. there was no secondary case.	2015	25555623
using surface-enhanced raman spectroscopy and electrochemically driven melting to discriminate yersinia pestis from y. pseudotuberculosis based on single nucleotide polymorphisms within unpurified polymerase chain reaction amplicons.	the development of sensors for the detection of pathogen-specific dna, including relevant species/strain level discrimination, is critical in molecular diagnostics with major impacts in areas such as bioterrorism and food safety. herein, we use electrochemically driven denaturation assays monitored by surface-enhanced raman spectroscopy (sers) to target single nucleotide polymorphisms (snps) that distinguish dna amplicons generated from yersinia pestis, the causative agent of plague, from the cl ...	2015	25551670
the trophic responses of two different rodent-vector-plague systems to climate change.	plague, the causative agent of three devastating pandemics in history, is currently a re-emerging disease, probably due to climate change and other anthropogenic changes. without understanding the response of plague systems to anthropogenic or climate changes in their trophic web, it is unfeasible to effectively predict years with high risks of plague outbreak, hampering our ability for effective prevention and control of the disease. here, by using surveillance data, we apply structural equatio ...	2015	25540277
lps modification promotes maintenance of yersinia pestis in fleas.	yersinia pestis, the causative agent of plague, can be transmitted by fleas by two different mechanisms: by early-phase transmission (ept), which occurs shortly after flea infection, or by blocked fleas following long-term infection. efficient flea-borne transmission is predicated upon the ability of y. pestis to be maintained within the flea. signature-tagged mutagenesis (stm) was used to identify genes required for y. pestis maintenance in a genuine plague vector, xenopsylla cheopis. the stm s ...	2015	25533446
pneumonic plague outbreak, northern madagascar, 2011.	yersinia pestis, the causative agent of plague, is endemic to madagascar, particularly to the central highlands. although plague has not been previously reported in northern madagascar, an outbreak of pneumonic plague occurred in this remote area in 2011. over a 27-day period, 17 suspected, 2 presumptive, and 3 confirmed human cases were identified, and all 15 untreated 20 patients died. molecular typing of y. pestis isolated from 2 survivors and 5 rattus rattus rat samples identified the madaga ...	2015	25530466
comparison of virulence between the yersinia pestis microtus 201, an avirulent strain to humans, and the vaccine strain ev in rhesus macaques, macaca mulatta.	our previous study has demonstrated that yersinia pestis microtus 201 is a low virulent strain to the chinese-origin rhesus macaques, macaca mulatta, and can protect it against high dose of virulent y. pestis challenge by subcutaneous route. to investigate whether the y. pestis microtus 201 can be used as a live attenuated vaccine candidate, in this study its intravenous virulence was determined and compared with the live attenuated vaccine strain ev in the chinese-origin rhesus macaque model. t ...	2014	25483697
hsp70 domain ii of mycobacterium tuberculosis modulates immune response and protective potential of f1 and lcrv antigens of yersinia pestis in a mouse model.	no ideal vaccine exists to control plague, a deadly dangerous disease caused by yersinia pestis. in this context, we cloned, expressed and purified recombinant f1, lcrv antigens of y. pestis and heat shock protein70 (hsp70) domain ii of m. tuberculosis in e. coli. to evaluate the protective potential of each purified protein alone or in combination, balb/c mice were immunized. humoral and cell mediated immune responses were evaluated. immunized animals were challenged with 100 ld50 of y. pestis ...	2014	25474358
a new class of salicylic acid derivatives for inhibiting yoph of yersinia pestis.	previously, we identified a class of salicylic acid derivatives that display inhibitory activity against the protein tyrosine phosphatase yoph from yersinia pestis. because docking study suggested that the large phenyl ring attaching to the salicylic acid core might be exposed to the solvent and might not contribute significantly to binding, we have developed a new class of compounds that no longer contain this phenyl ring. we first devised a synthetic scheme for the compounds and then developed ...	2014	25468042
kinetic epitope mapping of monoclonal antibodies raised against the yersinia pestis virulence factor lcrv.	five monoclonal antibodies, mab7.3, mab29.3, mab46.3, mab12.3 and mab36.3, raised to the lcrv virulence factor from yersinia pestis were characterised for their fab affinity against the purified protein and their fc affinity to protein a/g as a proxy for the fcγr receptor. kinetic measurements were performed label-free in a localised particle plasmon array reader. the fc-proteina/g complex first-order half-life was determined for each antibody and fell in the range of 0.8-3.8h. the fab first-ord ...	2015	25461137
silencing urease: a key evolutionary step that facilitated the adaptation of yersinia pestis to the flea-borne transmission route.	the arthropod-borne transmission route of yersinia pestis, the bacterial agent of plague, is a recent evolutionary adaptation. yersinia pseudotuberculosis, the closely related food-and water-borne enteric species from which y. pestis diverged less than 6,400 y ago, exhibits significant oral toxicity to the flea vectors of plague, whereas y. pestis does not. in this study, we identify the yersinia urease enzyme as the responsible oral toxin. all y. pestis strains, including those phylogenetically ...	2014	25453069
the role of pgac in klebsiella pneumoniae virulence and biofilm formation.	klebsiella pneumoniae has emerged as one of the major pathogens for community-acquired and nosocomial infections. a four-gene locus that had a high degree similarity with escherichia coli pgaabcd and yersinia pestis hmshfrs was identified in k. pneumoniae genomes. the pgaabcd in e. coli encodes the envelope-spanning pga machinery for the synthesis and secretion of poly-β-linked n-acetylglucosamine (pnag). in a limited number of phylogenetically diverse bacteria, pnag was demonstrated to mediate ...	2014	25450884
synthesis, antibacterial, antioxidant activity and qsar studies of novel 2-arylidenehydrazinyl-4-arylthiazole analogues.	a novel series of 2-arylidenehydrazinyl-4-arylthiazole analogues (3a-p) was designed and synthesized in excellent yields using a rapid, simple, efficient methodology. sixteen novel compounds were screened for in vitro antimicrobial activities against eleven bacteria, namely, staphylococcus aureus, listeria monocytogenes, enterococcus faecalis, bacillus subtilis, klebsiella pneumonia, citrobacter freundii, cronobacter sakazakii, salmonella enteritidis, escherichia coli, yersinia pestis, and pseud ...	2014	25450634
influence of the lipid membrane environment on structure and activity of the outer membrane protein ail from yersinia pestis.	the surrounding environment has significant consequences for the structural and functional properties of membrane proteins. while native structure and function can be reconstituted in lipid bilayer membranes, the detergents used for protein solubilization are not always compatible with biological activity and, hence, not always appropriate for direct detection of ligand binding by nmr spectroscopy. here we describe how the sample environment affects the activity of the outer membrane protein ail ...	2015	25433311
purification and biochemical characterisation of glmu from yersinia pestis.	antibiotic resistance has emerged as a real threat to mankind, rendering many compounds ineffective in the fight against bacterial infection, including for significant diseases such as plague caused by yersinia pestis. essential genes have been identified as promising targets for inhibiting with new classes of compounds. previously, the gene encoding the bifunctional udp-n-acetylglucosamine pyrophosphorylase/glucosamine-1-phosphate n-acetyltransferase enzyme glmu was confirmed as an essential ge ...	2015	25417006
crp acts as a transcriptional repressor of the ypo1635-phopq-ypo1632 operon in yersinia pestis.	yersinia pestis is the causative agent of plague. both cyclic amp receptor protein (crp) and phop are involved in regulating virulence-related genes in y. pestis. the phopq loci are transcribed as two distinct operons, ypo1635-phopq-ypo1632 and phopq-ypo1632. in the present work, the regulation of the first operon by crp was investigated using primer extension, lacz fusion, electrophoretic mobility shift assay, and dnase i footprinting assays. the results showed that crp bound to a dna region ov ...	2015	25413606
[genotyping on yersinia pestis isolated from yunnan province by clustered-regularly-interspaced-short palindromic-repeats].		2014	25394344
[regional genotyping and the geographical distribution regarding yersinia pestis isolates in china].	to type yersinia (y.) pestis isolates under different regions (dfr) and to observe their geographical distributions in china.	2014	25376688
immunopotentiation for bacterial biodefense.	activation of the innate immune system can enhance resistance to a variety of bacterial and viral infections. in situations where the etiological agent of disease is unknown, such as a bioterror attack, stimulation of innate immunity may be particularly useful as induced immune responses are often capable of providing protection against a broad range of pathogens. in particular, the threat of an intentional release of a highly virulent bacterial pathogen that is either intrinsically resistant to ...	2014	25373479
caspase-3 mediates the pathogenic effect of yersinia pestis yopm in liver of c57bl/6 mice and contributes to yopm's function in spleen.	the virulence protein yopm of the plague bacterium yersinia pestis has different dominant effects in liver and spleen. previous studies focused on spleen, where yopm inhibits accumulation of inflammatory dendritic cells. in the present study we focused on liver, where pmn function may be directly undermined by yopm without changes in inflammatory cell numbers in the initial days of infection, and foci of inflammation are easily identified. mice were infected with parent and δyopm-1 y. pestis kim ...	2014	25372388
coregulation of host-adapted metabolism and virulence by pathogenic yersiniae.	deciphering the principles how pathogenic bacteria adapt their metabolism to a specific host microenvironment is critical for understanding bacterial pathogenesis. the enteric pathogenic yersinia species yersinia pseudotuberculosis and yersinia enterocolitica and the causative agent of plague, yersinia pestis, are able to survive in a large variety of environmental reservoirs (e.g., soil, plants, insects) as well as warm-blooded animals (e.g., rodents, pigs, humans) with a particular preference ...	2014	25368845
transcriptional regulation of the waaae-coad operon by phop and rcsab in yersinia pestis biovar microtus.		2014	25359466
yersinia pestis targets neutrophils via complement receptor 3.	yersinia species display a tropism for lymphoid tissues during infection, and the bacteria select innate immune cells for delivery of cytotoxic effectors by the type iii secretion system. yet, the mechanism for target cell selection remains a mystery. here we investigate the interaction of yersinia pestis with murine splenocytes to identify factors that participate in the targeting process. we find that interactions with primary immune cells rely on multiple factors. first, the bacterial adhesin ...	2015	25359083
being prepared: bioterrorism and mass prophylaxis: part ii.	although several biological agents have been recognized as presenting a significant threat to public health if used in a bioterrorist attack, those that are of greatest importance are known as the category a agents: bacillus anthracis (anthrax); variola major (smallpox); yersinia pestis (plague); francisella tularensis (tularemia); ribonucleic acid viruses (hemorrhagic fevers); and clostridium botulinum (botulism toxin). in the previous issue, part i of this review focused on the clinical presen ...	2014	25356890
a bivalent typhoid live vector vaccine expressing both chromosome- and plasmid-encoded yersinia pestis antigens fully protects against murine lethal pulmonary plague infection.	live attenuated bacteria hold great promise as multivalent mucosal vaccines against a variety of pathogens. a major challenge of this approach has been the successful delivery of sufficient amounts of vaccine antigens to adequately prime the immune system without overattenuating the live vaccine. here we used a live attenuated salmonella enterica serovar typhi strain to create a bivalent mucosal plague vaccine that produces both the protective f1 capsular antigen of yersinia pestis and the lcrv ...	2015	25332120
draft genome sequences of yersinia pestis strains from the 1994 plague epidemic of surat and 2002 shimla outbreak in india.	we report the first draft genome sequences of the strains of plague-causing bacteria, yersinia pestis, from india. these include two strains from the surat epidemic (1994), one strain from the shimla outbreak (2002) and one strain from the plague surveillance activity in the deccan plateau region (1998). genome size for all four strains is ~4.49 million bp with 139-147 contigs. average sequencing depth for all four genomes was 21x.	2014	25320451
detection of rickettsia felis, rickettsia typhi, bartonella species and yersinia pestis in fleas (siphonaptera) from africa.	little is known about the presence/absence and prevalence of rickettsia spp, bartonella spp. and yersinia pestis in domestic and urban flea populations in tropical and subtropical african countries.	2014	25299702
a non-stationary relationship between global climate phenomena and human plague incidence in madagascar.	plague, a zoonosis caused by yersinia pestis, is found in asia and the americas, but predominantly in africa, with the island of madagascar reporting almost one third of human cases worldwide. plague's occurrence is affected by local climate factors which in turn are influenced by large-scale climate phenomena such as the el niño southern oscillation (enso). the effects of enso on regional climate are often enhanced or reduced by a second large-scale climate phenomenon, the indian ocean dipole ( ...	2014	25299064
caenorhabditis elegans bacterial pathogen resistant bus-4 mutants produce altered mucins.	caenorabditis elegans bus-4 glycosyltransferase mutants are resistant to infection by microbacterium nematophilum, yersinia pestis and yersinia pseudotuberculosis and have altered susceptibility to two leucobacter species verde1 and verde2. our objective in this study was to define the glycosylation changes leading to this phenotype to better understand how these changes lead to pathogen resistance. we performed maldi-tof ms, tandem ms and gc/ms experiments to reveal fine structural detail for t ...	2014	25296196
effect of nanovaccine chemistry on humoral immune response kinetics and maturation.	acute respiratory infections represent a significant portion of global morbidity and mortality annually. there is a critical need for efficacious vaccines against respiratory pathogens. to vaccinate against respiratory disease, pulmonary delivery is an attractive route because it mimics the route of natural infection and can confer both mucosal and systemic immunity. we have previously demonstrated that a single dose, intranasal vaccine based on polyanhydride nanoparticles elicited a protective ...	2014	25285425
evaluation of the effect of host immune status on short-term yersinia pestis infection in fleas with implications for the enzootic host model for maintenance of y. pestis during interepizootic periods.	plague, a primarily flea-borne disease caused by yersinia pestis, is characterized by rapidly spreading epizootics separated by periods of quiescence. little is known about how and where y. pestis persists between epizootics. it is commonly proposed, however, that y pestis is maintained during interepizootic periods in enzootic cycles involving flea vectors and relatively resistant host populations. according to this model, while susceptible individuals serve as infectious sources for feeding fl ...	2014	25276941