Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| tularemia associated with a hamster bite--colorado, 2004. | in april 2004, the colorado department of public health and environment (cdphe) was notified about a boy aged 3 years with diagnosed tularemia associated with a hamster bite. tularemia has not been associated previously with pet hamsters. cdphe conducted an investigation to determine whether other owners of hamsters were at risk. clinicians and public health officials should be aware that pet hamsters are a potential source of tularemia. | 2005 | 15635290 |
| francisella philomiragia adenitis and pulmonary nodules in a child with chronic granulomatous disease. | francisella philomiragia is a rare and opportunistic pathogen capable of producing invasive infection in patients with compromised neutrophil function and in patients that have survived a near-drowning. a case of f philomiragia adenitis and lung nodules, refractory to cephalosporin therapy, is reported in a 10-year-old boy with chronic granulomatous disease following a facial abrasion from a saltwater crab. to the authors' knowledge, this is the first canadian clinical isolate to be reported. ge ... | 2005 | 18159552 |
| [glandular tularemia--case report]. | tularemia is a rare zoonosis occuring in many clinical forms, including ulceral, glandular, oropharyngeal, pneumonic, and septic form. ent specialists seeing their patients in ambulatory and emergency settings are most likely to encounter oropharyngeal and glandular form. tularemia became widely discussed clinical entity in recent years due to its potential to being used as a biological weapon in acts of terrorism. authors present a case of a 75 yrs old woman treated for atypical tonsillitis wit ... | 2006 | 17357677 |
| real-time pcr for francisella tularensis types a and b. | 2006 | 17283646 | |
| [natural foci of tularemia on the wrangel island]. | the subjects of the study were snowy owl castings (611 samples), polar fox litters (148 samples), and water samples of outdoor tundra water reservoirs. tularemia antigen was sought in the castings and litters by the antibody neutralization test. the water was examined by bioassays. tularemia antigen was annually detected in the study samples. epizootically active autonomous natural foci of tundra-type tularemia were ascertained to continue to exist on the wrangel island. the major vectors of the ... | 2006 | 17290906 |
| [prevalence of antibodies to francisella tularensis in forest workers from different regions of poland]. | in the present study we evaluate the prevalence of antibodies to f. tularensis in 480 serum samples obtained from healthy forest workers from different regions of poland. the investigations were performed using the tube agglutination test and elisa. the cut-off limit of serum antibodies was set at mean antibody titre determined in the sera of 115 blood donors exceeded by three standard deviations. in none serum samples we detected antibodies to f. tularensis by tube agglutination test. of the 48 ... | 2006 | 17340995 |
| [francisella tularensis--feature of pathogen, pathogenesis, diagnostics]. | francisella tularensis belongs to the francisellaceae family. there are four known subspecies of francisella tularensis: tularensis, holarctica, mediasiatica and novicida. fully virulent strains possess a capsule, which protects f. tularensis from bactericidal action of serum. the main virulen factors of f. tularensis are 23-kda cytoplasmatic protein and lps. f tularensis mechanism of pathogenecity is very unique. f. lularensis affect macrophages using a cytochalasin b intensive pathway. bacteri ... | 2006 | 17249186 |
| characterization of recombinant francisella tularensis acid phosphatase a. | francisella tularensis is the etiologic agent of the potentially fatal human disease tularemia and is capable of survival and multiplication within professional phagocytes of the host. while the mechanisms that allow intracellular survival of the bacterium are only now beginning to be elucidated at the molecular level, previous work demonstrated that f. tularensis produces copious levels of an acid phosphatase which in crude and purified form affected the dose-dependent abrogation of the respira ... | 2006 | 15964202 |
| immunoproteomic analysis of the murine antibody response to successful and failed immunization with live anti-francisella vaccines. | francisella tularensis subspecies tularensis is one of the most virulent of bacterial pathogens for humans. protective immunity against the pathogen can be induced in humans and some, but not all, mouse strains by vaccination with live, but not killed, vaccines. in mice, this protection is mediated predominantly by cd4+ and cd8+ t cells. this is thought to be the case too for humans. nevertheless, it is possible that successful vaccination elicits antigen-specific antibodies that can serve as co ... | 2006 | 16781667 |
| identification, recombinant expression, immunolocalization in macrophages, and t-cell responsiveness of the major extracellular proteins of francisella tularensis. | a safer and more effective vaccine than the previously developed live attenuated vaccine is needed for combating francisella tularensis, a highly infectious bacterial pathogen. to search for potential candidates for inclusion in a new vaccine, we characterized the proteins present in the culture filtrates of a virulent recent clinical isolate and the attenuated live vaccine strain of f. tularensis using a proteomic approach. we identified a total of 12 proteins; among these, catalase-peroxidase ... | 2006 | 16790773 |
| identification of francisella tularensis genes affected by iron limitation. | cells of an attenuated live vaccine strain (lvs) of f. tularensis grown under iron-restricted conditions were found to contain increased quantities of several proteins relative to cells of this same strain grown under iron-replete conditions. mass spectrometric analysis identified two of these proteins as iglc and pdpb, both of which are encoded by genes located in a previously identified pathogenicity island in f. tularensis lvs. regions with homology to the consensus fur box sequence were loca ... | 2006 | 16790797 |
| differential infection of mononuclear phagocytes by francisella tularensis: role of the macrophage mannose receptor. | francisella tularensis (ft) is a gram-negative bacterium and the causative agent of tularemia. it is well established that this organism replicates inside macrophages, but we are only beginning to understand this interface at the molecular level. herein, we compared directly the ability of ft subspecies holarctica live-vaccine strain to infect freshly isolated human peripheral blood monocytes, monocyte-derived macrophages (mdm), and cells of the murine macrophage cell line j774a.1 (j774). we now ... | 2006 | 16816147 |
| population structure of francisella tularensis. | we have sequenced fragments of five metabolic housekeeping genes and two genes encoding outer membrane proteins from 81 isolates of francisella tularensis, representing all four subspecies. phylogenetic clustering of gene sequences from f. tularensis subsp. tularensis and f. tularensis subsp. holarctica aligned well with subspecies affiliations. in contrast, f. tularensis subsp. novicida and f. tularensis subsp. mediasiatica were indicated to be phylogenetically incoherent taxa. incongruent gene ... | 2006 | 16816208 |
| transcriptional profiling of the peripheral blood response during tularemia. | tularemia is a febrile disease caused by the highly contagious bacterium francisella tularensis. we undertook an analysis of the transcriptional response in peripheral blood during the course of ulceroglandular tularemia by use of affymetrix microarrays comprising 14,500 genes. samples were obtained from seven individuals at five occasions during 2 weeks after the first hospital visit and convalescent samples 3 months later. in total, 265 genes were differentially expressed, 95 of which at more ... | 2006 | 16826236 |
| [vntr-genotyping of francisella tularensis strains isolated in the former ussr territory and some european countries during epizootics in 1988 - 1989]. | retrospective vntr-analysis of 159 francisella tularensis subsp. holarctica strains isolated in december 1988 - february 1989 in former ussr and some european countries was carried out. analysis of heterogenic genotypes of strains allow to subdivide them into 30 groups of variants by individual genotypes, while cluster analysis--to subdivide them in 7 clusters with different number of compositions. the predominance of genotype c1 strains isolated on the rostov and archangelsk regions and the cri ... | 2006 | 16830584 |
| epidemiologic and molecular analysis of human tularemia, united states, 1964-2004. | tularemia in the united states is caused by 2 subspecies of francisella tularensis, subspecies tularensis (type a) and subspecies holarctica (type b). we compared clinical and demographic features of human tularemia cases from 1964 to 2004 from 39 states in which an isolate was recovered and subtyped. our data indicate that type a and type b infections differ with respect to affected populations, anatomic site of isolation, and geographic distribution. molecular subtyping with pulsed-field gel e ... | 2006 | 16836829 |
| the bla2 beta-lactamase from the live-vaccine strain of francisella tularensis encodes a functional protein that is only active against penicillin-class beta-lactam antibiotics. | francisella tularensis ssp. tularensis is a category a select agent and the causal organism for the zoonotic disease tularemia. the vast majority of f. tularensis isolates are beta-lactamase-positive. beta-lactamase production is widely believed to be responsible for the inefficacy of beta-lactams in the treatment of tularemia. in this study, we report the cloning and characterization of the two chromosomally encoded f. tularensis ssp. holarctica live-vaccine strain (lvs) beta-lactamases. the tw ... | 2006 | 16841206 |
| tularemia as a cause of fever in a squirrel monkey. | a 3-year-old female squirrel monkey (saimiri sciureus sciureus) was examined because of sudden onset of lethargy and fever. | 2006 | 16842053 |
| macrophage pro-inflammatory response to francisella novicida infection is regulated by ship. | francisella tularensis, a gram-negative facultative intracellular pathogen infecting principally macrophages and monocytes, is the etiological agent of tularemia. macrophage responses to f. tularensis infection include the production of pro-inflammatory cytokines such as interleukin (il)-12, which is critical for immunity against infection. molecular mechanisms regulating production of these inflammatory mediators are poorly understood. herein we report that the sh2 domain-containing inositol ph ... | 2006 | 16848641 |
| a microarray analysis of the murine macrophage response to infection with francisella tularensis lvs. | the response of cells of the mouse macrophage cell line j774 to infection with francisella tularensis lvs was analysed by means of a dna microarray representing approximately 18,500 genes (20,600 clones). the adaptive response was modest at all time points, and at most, 81 clones were differentially regulated from the time point of uptake of bacteria (0 min) up to 240 min later. for all five time points, 229 clones fulfilled the criteria of being differentially regulated, i.e. the ratio between ... | 2006 | 16849722 |
| critical role for serum opsonins and complement receptors cr3 (cd11b/cd18) and cr4 (cd11c/cd18) in phagocytosis of francisella tularensis by human dendritic cells (dc): uptake of francisella leads to activation of immature dc and intracellular survival of the bacteria. | francisella tularensis is one of the most infectious human pathogens known. although much has been learned about the immune response of mice using an attenuated live vaccine strain (lvs) derived from f. tularensis subspecies holarctica (type b), little is known about the responses of human monocyte-derived immature dendritic cells (dc). here, we show that optimal phagocytosis of lvs by dc is dependent on serum opsonization. we demonstrate that complement factor c3-derived opsonins and the major ... | 2006 | 16857732 |
| host usage and seasonal activity patterns of ixodes kingi and i. sculptus (acari: ixodidae) nymphs in a colorado prairie landscape, with a summary of published north american host records for all life stages. | we examined host usage and seasonal activity patterns of the nymphal stage of the ticks ixodes kingi and i. sculptus within a prairie rodent community in north-central colorado. ixodes kingi was commonly encountered on both northern grasshopper mice (onychomys leucogaster) and thirteen-lined ground squirrels (spermophilus tridecemlineatus), whereas i. sculptus frequently infested s. tridecemlineatus but was absent from o. leucogaster. low numbers of ticks of both species were collected from deer ... | 2006 | 16859106 |
| construction and characterization of an attenuated purine auxotroph in a francisella tularensis live vaccine strain. | francisella tularensis is a facultative intracellular pathogen and is the etiological agent of tularemia. it is capable of escaping from the phagosome, replicating to high numbers in the cytosol, and inducing apoptosis in macrophages of a variety of hosts. f. tularensis has received significant attention recently due to its potential use as a bioweapon. currently, there is no licensed vaccine against f. tularensis, although a partially protective live vaccine strain (lvs) that is attenuated in h ... | 2006 | 16861631 |
| virulence of francisella spp. in chicken embryos. | we examined the utility of infecting chicken embryos as a means of evaluating the virulence of different francisella sp. strains and mutants. infection of 7-day-old chicken embryos with a low dose of f. novicida or f. tularensis subsp. holarctica live vaccine strain (lvs) resulted in sustained growth for 6 days. different doses of these two organisms were used to inoculate chicken embryos to determine the time to death. these experiments showed that wild-type f. novicida was at least 10,000-fold ... | 2006 | 16861669 |
| identification of transposon insertion mutants of francisella tularensis tularensis strain schu s4 deficient in intracellular replication in the hepatic cell line hepg2. | francisella tularensis is a zoonotic intracellular bacterial pathogen that causes tularemia. the subspecies tularensis is highly virulent and is classified as a category a agent of biological warfare because of its low infectious dose by an aerosol route, and its ability to cause severe disease. in macrophages f. tularensis exhibits a rather novel intracellular lifestyle; after invasion it remains in a phagosome for three to six hours before escaping to, and replicating in the cytoplasm. the mol ... | 2006 | 16879747 |
| uptake of serum-opsonized francisella tularensis by macrophages can be mediated by class a scavenger receptors. | the bacterium francisella tularensis is highly infective, and this is one of the chief attributes that has led to its development as a bioweapon. establishment of infection requires efficient uptake of f. tularensis by host macrophages, which provide a safe in vivo environment for f. tularensis replication. little is known, however, about the cellular entry mechanisms employed by this organism. this report shows that efficient uptake of f. tularensis live vaccine strain (lvs) by macrophages is d ... | 2006 | 16882038 |
| paired-end sequence mapping detects extensive genomic rearrangement and translocation during divergence of francisella tularensis subsp. tularensis and francisella tularensis subsp. holarctica populations. | comparative genome hybridization of the francisella tularensis subsp. tularensis and f. tularensis subsp. holarctica populations have shown that genome content is highly conserved, with relatively few genes in the f. tularensis subsp. tularensis genome being absent in other f. tularensis subspecies. to determine if organization of the genome differs between global populations of f. tularensis subsp. tularensis and f. tularensis subsp. holarctica, we have used paired-end sequence mapping (pesm) t ... | 2006 | 16885459 |
| superoxide dismutase b gene (sodb)-deficient mutants of francisella tularensis demonstrate hypersensitivity to oxidative stress and attenuated virulence. | a francisella tularensis live vaccine strain mutant (sodb(ft)) with reduced fe-superoxide dismutase gene expression was generated and found to exhibit decreased sodb activity and increased sensitivity to redox cycling compounds compared to wild-type bacteria. the sodb(ft) mutant also was significantly attenuated for virulence in mice. thus, this study has identified sodb as an important f. tularensis virulence factor. | 2006 | 16923916 |
| attenuated francisella novicida transposon mutants protect mice against wild-type challenge. | francisella tularensis is the bacterial pathogen that causes tularemia in humans and a number of animals. to date, there is no approved vaccine for this widespread and life-threatening disease. the goal of this study was to identify f. tularensis mutants that can be used in the development of a live attenuated vaccine. we screened f. novicida transposon mutants to identify mutants that exhibited reduced growth in mouse macrophages, as these cells are the preferred host cells of francisella and a ... | 2006 | 16926401 |
| characterization of the receptor-ligand pathways important for entry and survival of francisella tularensis in human macrophages. | inhalational pneumonic tularemia, caused by francisella tularensis, is lethal in humans. f. tularensis is phagocytosed by macrophages followed by escape from phagosomes into the cytoplasm. little is known of the phagocytic mechanisms for francisella, particularly as they relate to the lung and alveolar macrophages. here we examined receptors on primary human monocytes and macrophages which mediate the phagocytosis and intracellular survival of f. novicida. f. novicida association with monocyte-d ... | 2006 | 16926403 |
| tularemia, a reemerging disease in northwest turkey: epidemiological investigation and evaluation of treatment responses. | an outbreak of tularemia occurred in three provinces in turkey in february 2004 and reemerged in the same provinces in february 2005. a total of 61 cases, 54 of which were confirmed with the micro-agglutination test, were diagnosed with oropharyngeal tularemia. no culture for francisella tularensis was attempted, but pcr for f. tularensis was positive in aspiration material of suppurated lymphadenitis of 7 patients. f. tularensis detection with pcr was negative in water samples, but epidemiologi ... | 2006 | 16936340 |
| [immunization with cellulose-immobilized antigens. the development of a. e. gurvitch concept]. | a highly purified tul4-cbd chimeric protein was obtained by one stage purification method. tul4-cbd protein consists of tul4 francisella tularensis mature peptide sequence, gly-ser spacer and cellulose binding domain (cbd) of anaerocellum thermophilum. the tul4-cbd protein was shown to induce production of specific antibodies to tul4 protein in laboratory animals. | 2006 | 16941875 |
| identification of a francisella tularensis lvs outer membrane protein that confers adherence to a549 human lung cells. | francisella tularensis is a highly pathogenic bacterium; however, little is known about its initial interactions with mucosal surfaces of the human respiratory tract. to investigate these interactions, we tested whether two francisella strains could adhere to a549 human lung epithelial cells. we found that lvs adhered well to these cells while francisella novicida adhered poorly. we used surface biotinylation to identify bacterial proteins that might mediate this adherence. we report the identif ... | 2006 | 16958857 |
| chromosome rearrangement and diversification of francisella tularensis revealed by the type b (osu18) genome sequence. | the gamma-proteobacterium francisella tularensis is one of the most infectious human pathogens, and the highly virulent organism f. tularensis subsp. tularensis (type a) and less virulent organism f. tularensis subsp. holarctica (type b) are most commonly associated with significant disease in humans and animals. here we report the complete genome sequence and annotation for a low-passage type b strain (osu18) isolated from a dead beaver found near red rock, okla., in 1978. a comparison of the f ... | 2006 | 16980500 |
| lack of in vitro and in vivo recognition of francisella tularensis subspecies lipopolysaccharide by toll-like receptors. | francisella tularensis is an intracellular gram-negative bacterium that is highly infectious and potentially lethal. several subspecies exist of varying pathogenicity. infection by only a few organisms is sufficient to cause disease depending on the model system. lipopolysaccharide (lps) of gram-negative bacteria is generally recognized by toll-like receptor 4 (tlr4)/md-2 and induces a strong proinflammatory response. examination of human clinical f. tularensis isolates revealed that human virul ... | 2006 | 16982824 |
| autophagy-mediated reentry of francisella tularensis into the endocytic compartment after cytoplasmic replication. | intracellular bacterial pathogens evade the bactericidal functions of mammalian cells by physical escape from their phagosome and replication into the cytoplasm or through the modulation of phagosome maturation and biogenesis of a membrane-bound replicative organelle. here, we detail in murine primary macrophages the intracellular life cycle of francisella tularensis, a highly infectious bacterium that survives and replicates within mammalian cells. after transient interactions with the endocyti ... | 2006 | 16983090 |
| type iv pili-mediated secretion modulates francisella virulence. | francisella tularensis are the causative agent of the zoonotic disease, tularaemia. among four f. tularensis subspecies, ssp. novicida (f. novicida) is pathogenic only for immunocompromised individuals, while all four subspecies are pathogenic for mice. this study utilized proteomic and bioinformatic approaches to identify seven f. novicida secreted proteins and the corresponding type iv pilus (t4p) secretion system. the secreted proteins were predicted to encode two chitinases, a chitin binding ... | 2006 | 16987180 |
| francisella tularensis lvs grown in macrophages has reduced ability to stimulate the secretion of inflammatory cytokines by macrophages in vitro. | the virulence of francisella tularensis lvs is determined in part by its ability to invade and replicate within macrophages and stimulate the production of inflammatory cytokines. the present study determined the effects of growing f. tularensis in macrophages on its ability to stimulate cytokine secretion by macrophages. f. tularensis grown in mueller-hinton broth (ftb) stimulated the secretion of large amounts of tnf-alpha, il-12p40, il-6 and mcp-1/ccl2 when incubated with macrophages overnigh ... | 2006 | 16996713 |
| potential source of francisella tularensis live vaccine strain attenuation determined by genome comparison. | francisella tularensis is a bacterial pathogen that causes the zoonotic disease tularemia and is important to biodefense. currently, the only vaccine known to confer protection against tularemia is a specific live vaccine strain (designated lvs) derived from a virulent isolate of francisella tularensis subsp. holarctica. the origin and source of attenuation of this strain are not known. to assist with the design of a defined live vaccine strain, we sought to determine the genetic basis of the at ... | 2006 | 17000723 |
| mac-1+ cells are the predominant subset in the early hepatic lesions of mice infected with francisella tularensis. | the cell composition of early hepatic lesions of experimental murine tularemia has not been characterized with specific markers. the appearance of multiple granulomatous-necrotic lesions in the liver correlates with a marked increase in the levels of serum alanine transferase and lactate dehydrogenase. francisella tularensis, detected by specific antibodies, can be first noted by day 1 and becomes associated with the lesions by 5 days postinoculation. these lesions become necrotic, with some evi ... | 2006 | 17000726 |
| identification of mgla-regulated genes reveals novel virulence factors in francisella tularensis. | the facultative intracellular bacterium francisella tularensis causes the zoonotic disease tularemia. f. tularensis resides within host macrophages in vivo, and this ability is essential for pathogenesis. the transcription factor mgla is required for the expression of several francisella genes that are necessary for replication in macrophages and for virulence in mice. we hypothesized that the identification of mgla-regulated genes in the francisella genome by transcriptional profiling of wild-t ... | 2006 | 17000729 |
| interview with dr. lee-ann allen regarding pivotal advance: francisella tularensis lvs evades killing by human neutrophils via inhibition of the respiratory burst and phagosome escape. interview by helene f. rosenberg. | 2006 | 17005906 | |
| the identification and evaluation of atp binding cassette systems in the intracellular bacterium francisella tularensis. | francisella tularensis is a facultative intracellular bacterium responsible for the disease tularemia. analysis of the fully sequenced genome of the virulent f. tularensis strain schu s4 has led to the identification of twenty atp binding cassette (abc) systems, of which five appear to be non-functional. the fifteen complete systems comprise three importers, five exporters, four systems involved in non-transport processes, and three systems of unknown or ill-defined function. the number and clas ... | 2006 | 16503121 |
| antibiotic selection and resistance issues with fluoroquinolones and doxycycline against bioterrorism agents. | bacillus anthracis (anthrax), yersinia pestis (plague), francisella tularensis (tularemia), coxiella burnetti (q fever), and brucella sp (brucellosis) are all potential bioterrorism agents. their known virulence, potential lethality, and ability to develop resistance to known antibiotic treatments make these pathogens particularly dangerous. we reviewed the scientific literature by searching medline databases and published abstracts from the interscience conference on antimicrobial agents and ch ... | 2006 | 16506347 |
| crystallization of a newly discovered histidine acid phosphatase from francisella tularensis. | francisella tularensis is a highly infectious bacterial pathogen that is considered by the centers for disease control and prevention to be a potential bioterrorism weapon. here, the crystallization of a 37.2 kda phosphatase encoded by the genome of f. tularensis subsp. holarctica live vaccine strain is reported. this enzyme shares 41% amino-acid sequence identity with legionella pneumophila major acid phosphatase and contains the rhgxrxp motif that is characteristic of the histidine acid phosph ... | 2006 | 16511256 |
| innate immune response to francisella tularensis is mediated by tlr2 and caspase-1 activation. | francisella tularensis, a gram-negative, facultative, intracellular bacterium, is the etiologic agent of tularemia and a category a bioterrorism agent. little is known about the mechanism of pathogenesis of tularemia. in this paper, we describe the interaction of the live vaccine strain of f. tularensis with the innate immune system. we have found that in human and mouse dendritic cells, f. tularensis elicited a powerful inflammatory response, characterized by production of a number of cytokines ... | 2006 | 16895974 |
| structure of francisella tularensis acpa: prototype of a unique superfamily of acid phosphatases and phospholipases c. | acpa is a respiratory burst-inhibiting acid phosphatase from the centers for disease control and prevention category a bioterrorism agent francisella tularensis and prototype of a superfamily of acid phosphatases and phospholipases c. we report the 1.75-a resolution crystal structure of acpa complexed with the inhibitor orthovanadate, which is the first structure of any f. tularensis protein and the first for any member of this superfamily. the core domain is a twisted 8-stranded beta-sheet flan ... | 2006 | 16899453 |
| francisella tularensis lvs evades killing by human neutrophils via inhibition of the respiratory burst and phagosome escape. | francisella tularensis is a gram-negative bacterium and the causative agent of tularemia. recent data indicate that f. tularensis replicates inside macrophages, but its fate in other cell types, including human neutrophils, is unclear. we now show that f. tularensis live vaccine strain (lvs), opsonized with normal human serum, was rapidly ingested by neutrophils but was not eliminated. moreover, evasion of intracellular killing can be explained, in part, by disruption of the respiratory burst. a ... | 2006 | 16908516 |
| deletion of tolc orthologs in francisella tularensis identifies roles in multidrug resistance and virulence. | the gram-negative bacterium francisella tularensis is the causative agent of tularemia. interest in this zoonotic pathogen has increased due to its classification as a category a agent of bioterrorism, but little is known about the molecular mechanisms underlying its virulence, and especially what secretion systems and virulence factors are present. in this study, we characterized two genes in the f. tularensis genome, tolc and a gene we term ftlc, whose products have high homology with the esch ... | 2006 | 16908853 |
| live vaccine strain francisella tularensis is detectable at the inoculation site but not in blood after vaccination against tularemia. | live vaccine strain (lvs) francisella tularensis is a live, attenuated investigational tularemia vaccine that has been used by the us army for decades to protect laboratory workers. postvaccination bacterial kinetic characteristics of lvs at the inoculation site and in the blood are unknown and, therefore, were assessed in a prospective study. lvs vaccination of laboratory workers provided the opportunity to compare culture with polymerase chain reaction (pcr) for the detection of f. tularensis ... | 2006 | 16912944 |
| akt/protein kinase b modulates macrophage inflammatory response to francisella infection and confers a survival advantage in mice. | the gram-negative bacterium francisella novicida infects primarily monocytes/macrophages and is highly virulent in mice. macrophages respond by producing inflammatory cytokines that confer immunity against the infection. however, the molecular details of host cell response to francisella infection are poorly understood. in this study, we demonstrate that f. novicida infection of murine macrophages induces the activation of akt. inhibition of akt significantly decreases proinflammatory cytokine p ... | 2006 | 17056562 |
| genetic tools for highly pathogenic francisella tularensis subsp. tularensis. | this paper is the first detailed description of the development and use of new genetic tools specifically for the safe manipulation of highly pathogenic francisella tularensis subsp. tularensis. most of these tools are also demonstrated to work with other f. tularensis subspecies. kanamycin and hygromycin resistance determinants that function as genetic markers in f. tularensis subsp. tularensis strain schu and sets of episomal shuttle vectors that are either unstable or stably maintained in the ... | 2006 | 17074911 |
| large tularaemia outbreak in varmland, central sweden, 2006. | 2006 | 17075151 | |
| comparative proteome analysis of fractions enriched for membrane-associated proteins from francisella tularensis subsp. tularensis and f. tularensis subsp. holarctica strains. | the facultative intracellular pathogen francisella tularensis is the causative agent of the serious infectious disease tularemia. despite intensive research, the virulence factors and pathogenetic mechanisms remain largely unknown. to identify novel putative virulence factors, we carried out a comparative proteome analysis of fractions enriched for membrane-associated proteins isolated from the highly virulent subspecies tularensis strain schu s4 and three representatives of subspecies holarctic ... | 2006 | 17081064 |
| multiplexed serology in atypical bacterial pneumonia. | atypical pneumonia is a term applied to lower respiratory tract infections that are not characterized by signs and symptoms of lobar consolidation. this article will discuss the epidemiology, clinical manifestations, and laboratory diagnoses of mycoplasma pneumoniae, chlamydia sp., legionella sp., francisella tularensis, and coxiella burnetii, which are the agents most commonly associated with atypical pneumonia. because many of these pathogens are intracellular, diagnosis depends upon serologic ... | 2006 | 17114771 |
| structure and biosynthesis of free lipid a molecules that replace lipopolysaccharide in francisella tularensis subsp. novicida. | francisella tularensis subsp. novicida u112 phospholipids, extracted without hydrolysis, consist mainly of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and two lipid a species, designated a1 and a2. these lipid a species, present in a ratio of 7:1, comprise 15% of the total phospholipids, as judged by 32pi labeling. although lipopolysaccharide is detectable in f. tularensis subsp. novicida u112, less than 5% of the total lipid a is covalently linked to it. a1 and a2 were ... | 2006 | 17128982 |
| aquatic francisella-like bacterium associated with mortality of intensively cultured hybrid striped bass morone chrysops x m. saxatilis. | the present study identifies an emerging disease associated with an aquatic francisella-like bacterium that can cause mortality in hybrid striped bass morone chrysops x m. saxatilis reared intensively in freshwater. clinically affected fish were lethargic, had scattered haemorrhagic cutaneous lesions and diffuse gill pallor. the head kidney and spleen were markedly swollen and contained numerous interstitial granulomas; histological examination revealed small, pleomorphic gram-negative coccobaci ... | 2006 | 17140136 |
| tularemia re-emerging in european part of turkey after 60 years. | the aim of this study was to investigate a tularemia outbreak in the thrace region of turkey. the outbreak occurred in demirkoy village of edirne, in 2005. of 400 villagers, 266 were examined and their sera were taken. throat swabs and lymph node aspirates were cultured. specific antibodies in patients and domestic animals were screened by a microagglutination test. pcr assays and cultures of the samples of patients, animal tissues, and water sources were performed, along with active surveillanc ... | 2006 | 17186960 |
| development of a real-time pcr assay for detection and quantification of francisella tularensis. | the facultative intracellular bacterium, francisella tularensis, is an etiological agent of tularemia and is also considered to be a potential biological threat agent due to its extreme infectivity. we established a real-time pcr assay using the lightcycler (lc) system to detect a francisella-specific sequence of the outer membrane protein (fopa) gene. twenty-five f. tularensis strains including 16 japanese isolates were subjected to this lc-pcr assay, and were tested positive, whereas francisel ... | 2006 | 16495634 |
| virulence comparison in mice of distinct isolates of type a francisella tularensis. | francisella tularensis subspecies tularensis (type a f. tularensis) is considered to be one of the most virulent of all bacterial pathogens. mice are extremely susceptible to infection with this subspecies (ld100 via various inoculation routes is <10 cfu). however, it has not been established whether overt virulence differences exist amongst type a strains of f. tularensis. to this end, the present study compared the virulence of two distinct type a strains, fsc033 and schu s4, for naïve mice an ... | 2006 | 16448801 |
| expression cloning and periplasmic orientation of the francisella novicida lipid a 4'-phosphatase lpxf. | francisella tularensis and related intracellular pathogens synthesize lipid a molecules that differ from their escherichia coli counterparts. although a functional orthologue of lpxk, the gene encoding the lipid a 4'-kinase, is present in francisella, no 4'-phosphate moiety is attached to francisella lipid a. we now demonstrate that a membrane-bound phosphatase present in francisella novicida u112 selectively removes the 4'-phosphate residue from tetra- and pentaacylated lipid a molecules. a clo ... | 2006 | 16467300 |
| transcriptional profiling of host responses in mouse lungs following aerosol infection with type a francisella tularensis. | tularaemia caused by inhalation of type a francisella tularensis bacteria is one of the most aggressive infectious diseases known, but the reasons for the very rapid spread of the organism from the lungs to internal organs and the ensuing mortality are unknown. the present study used the mouse model to examine in detail the host immune response in the lung. after an aerosol challenge with 20 c.f.u. of the type a strain fsc033, all mice developed clinical signs of severe disease, showed weight lo ... | 2006 | 16476789 |
| fiber-optic microsphere-based arrays for multiplexed biological warfare agent detection. | we report a multiplexed high-density dna array capable of rapid, sensitive, and reliable identification of potential biological warfare agents. an optical fiber bundle containing 6000 individual 3.1-mum-diameter fibers was chemically etched to yield microwells and used as the substrate for the array. eighteen different 50-mer single-stranded dna probes were covalently attached to 3.1-mum microspheres. probe sequences were designed for bacillus anthracis, yersinia pestis, francisella tularensis, ... | 2006 | 16478092 |
| h2bc: a new technique for nmr analysis of complex carbohydrates. | it is demonstrated that the h2bc nmr pulse sequence (j. am. chem. soc.2005, 127, 6154, magn. reson. chem.2005, 43, 971-974) offers unambiguous assignments and significant simplification of nmr spectra of large and complex carbohydrates compared to other techniques for the establishment of correlations over more than one bond. h2bc almost exclusively correlates protons and proton-bearing carbon spins separated by two covalent bonds and is independent of occasionally vanishing (2)j(ch) coupling co ... | 2006 | 16406276 |
| cryopyrin activates the inflammasome in response to toxins and atp. | a crucial part of the innate immune response is the assembly of the inflammasome, a cytosolic complex of proteins that activates caspase-1 to process the proinflammatory cytokines interleukin (il)-1beta and il-18. the adaptor protein asc is essential for inflammasome function, binding directly to caspase-1 (refs 3, 4), but the triggers of this interaction are less clear. asc also interacts with the adaptor cryopyrin (also known as nalp3 or cias1). activating mutations in cryopyrin are associated ... | 2006 | 16407890 |
| bacterial cell microarrays for the detection and characterization of antibodies against surface antigens. | bacterial cell surface antigens interact with the host immune system resulting in the production of antibodies. detection of antibodies against surface antigens has applications in diagnosis of many bacterial infections, assessment of immune status and epidemiological studies. we developed a microarray platform, for antibody detection, by printing gram-negative and gram-positive whole bacterial cells on nitrocellulose coated glass substrates. antibody binding was detected using fluorophore label ... | 2006 | 16423364 |
| detection of biological threat agents by real-time pcr: comparison of assay performance on the r.a.p.i.d., the lightcycler, and the smart cycler platforms. | rapid detection of biological threat agents is critical for timely therapeutic administration. fluorogenic pcr provides a rapid, sensitive, and specific tool for molecular identification of these agents. we compared the performance of assays for 7 biological threat agents on the idaho technology, inc. r.a.p.i.d., the roche lightcycler, and the cepheid smart cycler. | 2006 | 16391330 |
| internalization and phagosome escape required for francisella to induce human monocyte il-1beta processing and release. | macrophage responses to francisella infection have been characterized previously by subdued proinflammatory responses; however, these studies have generally focused on macrophage cell lines or monocyte-derived macrophages. therefore, we studied the ability of fresh human blood monocytes to engulf and respond to francisella by using the live vaccine strain variant and francisella novicida. because francisella organisms have been reported to escape from the phagolysosome into the cytosol, we hypot ... | 2006 | 16373510 |
| myeloid differentiation factor-88 (myd88) is essential for control of primary in vivo francisella tularensis lvs infection, but not for control of intra-macrophage bacterial replication. | the means by which francisella tularensis, the causative agent of tularemia, are recognized by mammalian immune systems are poorly understood. here we wished to explore the contribution of the myd88/toll-like receptor signaling pathway in initiating murine responses to f. tularensis live vaccine strain (lvs). myd88 knockout (ko) mice, but not tlr2-, tlr4- or tlr9-deficient mice, rapidly succumbed following in vivo bacterial infection via the intradermal route even with a very low dose of lvs (5 ... | 2006 | 16513388 |
| in vivo himar1-based transposon mutagenesis of francisella tularensis. | francisella tularensis is the intracellular pathogen that causes human tularemia. it is recognized as a potential agent of bioterrorism due to its low infectious dose and multiple routes of entry. we report the development of a himar1-based random mutagenesis system for f. tularensis (himarft). in vivo mutagenesis of f. tularensis live vaccine strain (lvs) with himarft occurs at high efficiency. approximately 12 to 15% of cells transformed with the delivery plasmid result in transposon insertion ... | 2006 | 16517634 |
| an outbreak of airborne tularaemia in france, august 2004. | fifteen tularaemia cases were identified after a holiday spent at a converted mill in the vendee region in france, between 9 and 12 august 2004. the mill was visited, and descriptive, retrospective cohort and environmental investigations were conducted. the 39 people who had stayed at the mill between 24 july and 11 august were asked about symptoms, exposure to food and animals, and leisure activities. a case was defined as a person with evidence of fever and a positive serology (seroconversion ... | 2006 | 16525197 |
| [persistence factors of francisella tularensis]. | the study of the persistence potential of 64 f. tularensis strains isolated from different sources was carried out. the wide spread of the antilysozyme, antilactoferrin and anticomplementory activities of f. tularensis were detected. f. tularensis, isolated from ticks and water, were characterized by the highest level of the expression of antilysozyme activity, while anticomplementory and antilactoferrin activities of the infective agents were characteristic of those microorganisms which were is ... | 2006 | 16532645 |
| anti-francisella tularensis dna aptamers detect tularemia antigen from different subspecies by aptamer-linked immobilized sorbent assay. | aptamers are powerful candidates for molecular detection of targets due to their unique recognition properties. these affinity probes can be used to recognize and bind to their targets in the various types of assays that are currently used to detect and capture molecules of interest. they are short single-stranded (ss) oligonucleotides composed of dna or rna sequences that are selected in vitro based on their affinity and specificity for the target. using combinatorial oligonucleotide libraries, ... | 2006 | 16550191 |
| intranasal vaccination with a defined attenuated francisella novicida strain induces gamma interferon-dependent antibody-mediated protection against tularemia. | francisella tularensis is an intracellular gram-negative bacterium that is the causative agent of tularemia and a potential bioweapon. we have characterized the efficacy of a defined f. novicida mutant (deltaiglc) as a live attenuated vaccine against subsequent intranasal challenge with the wild-type organism. animals primed with the f. novicida deltaiglc (kkf24) mutant induced robust splenic gamma interferon (ifn-gamma) and interleukin-12 (il-12) recall responses with negligible il-4 production ... | 2006 | 16552035 |
| direct repeat-mediated deletion of a type iv pilin gene results in major virulence attenuation of francisella tularensis. | francisella tularensis, the causative agent of tularaemia, is a highly infectious and virulent intracellular pathogen. there are two main human pathogenic subspecies, francisella tularensis ssp. tularensis (type a), and francisella tularensis ssp. holarctica (type b). so far, knowledge regarding key virulence determinants is limited but it is clear that intracellular survival and multiplication is one major virulence strategy of francisella. in addition, genome sequencing has revealed the presen ... | 2006 | 16553886 |
| tularemia induced bilateral optic neuritis. | 2006 | 16562762 | |
| francisella tularensis lps induces the production of cytokines in human monocytes and signals via toll-like receptor 4 with much lower potency than e. coli lps. | francisella tularensis is a virulent gram-negative intracellular pathogen. to address the signaling routes involved in the response of host cells to lps from f. tularensis live vaccine strain (lvs), experiments were performed in transiently transfected 293 cells. induction of kappab-driven transcriptional activity by 2.5 mug ml(-1) f. tularensis lps isolated by phenol-water and ether-water extraction, was observed in cells transfected with toll-like receptor (tlr) 4 and md-2, although cd14 was r ... | 2006 | 16574669 |
| francisella sp. (family francisellaceae) causing mortality in norwegian cod (gadus morhua) farming. | in 2004, a new disease was detected in cod (gadus morhua) in western norway. affected cod had white granulomas in the visceral organs and skin. a species of francisella was isolated on blood agar plates from moribund cod. the bacterium could be grown at temperatures ranging from 6 to 22 degrees c, but did not grow at 37 degrees c. challenge experiments showed that francisella sp. was the cause for the new disease. the 16s rdna gene sequence from francisella sp. showed 99.17% similarity to f. phi ... | 2006 | 16614828 |
| [tularaemia as a differential diagnosis in tumour colli]. | tularaemia is a bacterial zoonosis caused by the bacterium francisella tularensis. different species of rodents and small mammals are the main reservoir; the transmission of disease is caused by direct contact with diseased animals, via insect vectors, or by ingestion of contaminated food and water. the disease is known to cause a complex clinical presentation in which head and neck manifestations are common. it occurs at a low annual rate in the northern and middle regions of norway, but in rec ... | 2006 | 16619065 |
| treatment of murine pneumonic francisella tularensis infection with gatifloxacin, moxifloxacin or ciprofloxacin. | the efficacies of gatifloxacin and moxifloxacin were assessed in a balb/c mouse model of pneumonic tularemia and compared with the efficacy of ciprofloxacin. the rate of relapse following dexamethasone treatment was also investigated. mice were given 100 mg/kg of the antibiotic by oral administration twice daily for 14 days following an aerosol challenge. all three fluoroquinolones prevented disease during the treatment period, but significant failure rates occurred after the cessation of therap ... | 2006 | 16621457 |
| toll-like receptor 2 is required for inflammatory responses to francisella tularensis lvs. | francisella tularensis, a gram-negative bacterium, is the etiologic agent of tularemia and has recently been classified as a category a bioterrorism agent. infections with f. tularensis result in an inflammatory response that plays an important role in the pathogenesis of the disease; however, the cellular mechanisms mediating this response have not been completely elucidated. in the present study, we determined the role of toll-like receptors (tlrs) in mediating inflammatory responses to f. tul ... | 2006 | 16622218 |
| a simple and rapid protein array based method for the simultaneous detection of biowarfare agents. | a protein chip has been developed that allows the simultaneous detection of a multitude of different biowarfare agents. the chip was developed for the arraytube platform providing a cheap and easy to handle technology solution that combines a microtube-integrated protein chip with the classical procedure of a sandwich-enzyme-linked immunosorbent assay and signal amplification by streptavidin-poly-horseradish peroxidase. specific immunoassays for staphylococcus enterotoxin b, ricin, venezuelan eq ... | 2006 | 16622830 |
| the atypical pneumonias: clinical diagnosis and importance. | the most common atypical pneumonias are caused by three zoonotic pathogens, chlamydia psittaci (psittacosis), francisella tularensis (tularemia), and coxiella burnetii (q fever), and three nonzoonotic pathogens, chlamydia pneumoniae, mycoplasma pneumoniae, and legionella. these atypical agents, unlike the typical pathogens, often cause extrapulmonary manifestations. atypical caps are systemic infectious diseases with a pulmonary component and may be differentiated clinically from typical caps by ... | 2006 | 16669925 |
| dominance of human innate immune responses in primary francisella tularensis live vaccine strain vaccination. | 2006 | 16675351 | |
| a novel systemic granulomatous inflammatory disease in farmed atlantic cod, gadus morhua l., associated with a bacterium belonging to the genus francisella. | 2006 | 16677321 | |
| environmental survey for four pathogenic bacteria and closely related species using phylogenetic and functional genes. | bacterial species with high dna sequence similarity to pathogens could affect the specificity of assays designed to detect biological threat agents in environmental samples. the natural presence of four pathogenic bacteria, bacillus anthracis, clostridium perfringens, francisella tularensis, and yersinia pestis and their closely related species, was determined for a large collection of soil and aerosol samples. polymerase chain reaction (pcr) and gene sequencing were used using group-specific 16 ... | 2006 | 16696701 |
| francisella tularensis: taxonomy, genetics, and immunopathogenesis of a potential agent of biowarfare. | tularemia is a zoonosis of humans caused by infection with the facultative intracellular bacterium francisella tularensis. interest in f. tularensis has increased markedly in the past few years because of its potential use as an agent of bioterrorism. five subspecies of this organism are found in the northern hemisphere, but only f. tularensis subsp. tularensis and subsp. holarctica cause disease in humans. this review summarizes what is known about the pathogenesis of tularemia with a focus on ... | 2006 | 16704343 |
| tularemia outbreak, bulgaria, 1997-2005. | the 1997-2005 tularemia outbreak in bulgaria affected 285 people. ten strains were isolated from humans, a tick, a hare, and water. amplified fragment length polymorphism typing of the present isolates and of the strain isolated in 1962 suggests that a new genetic variant caused the outbreak. | 2006 | 16704820 |
| francisella tularensis in rodents, china. | a total of 420 rodents in china were examined for francisella tularensis by polymerase chain reaction. the infection rates were 4.76% in total, and 11.65%, 10.00%, 6.56%, 1.77%, and 0% in jilin, xinjiang, heilongjiang, inner mongolia, and zhejiang, respectively. sequence analysis showed that all the detected agents belonged to f. tularensis subsp. holarctica. | 2006 | 16707060 |
| raccoons and skunks as sentinels for enzootic tularemia. | we analyzed sera from diverse mammals of martha's vineyard, massachusetts, for evidence of francisella tularensis exposure. skunks and raccoons were frequently seroreactive, whereas white-footed mice, cottontail rabbits, deer, rats, and dogs were not. tularemia surveillance may be facilitated by focusing on skunks and raccoons. | 2006 | 16707067 |
| characterization of the siderophore of francisella tularensis and role of fsla in siderophore production. | we determined that lvs and schu s4 strains of the human pathogen francisella tularensis express a siderophore when grown under iron-limiting conditions. we purified this siderophore by conventional column chromatography and high-pressure liquid chromatography and used mass spectrometric analysis to demonstrate that it is structurally similar to the polycarboxylate siderophore rhizoferrin. the siderophore promoted the growth of lvs and schu s4 strains in iron-limiting media. we identified a poten ... | 2006 | 16707671 |
| immunologic consequences of francisella tularensis live vaccine strain infection: role of the innate immune response in infection and immunity. | francisella tularensis (ft), a gram-negative intracellular bacterium, is the etiologic agent of tularemia. although attenuated for humans, i.p. infection of mice with <10 ft live vaccine strain (lvs) organisms causes lethal infection that resembles human tularemia, whereas the ld50 for an intradermal infection is >10(6) organisms. to examine the immunological consequences of ft lvs infection on the innate immune response, the inflammatory responses of mice infected i.p. or intradermally were com ... | 2006 | 16709849 |
| basis for the failure of francisella tularensis lipopolysaccharide to prime human polymorphonuclear leukocytes. | francisella tularensis is the intracellular gram-negative coccobacillus that causes tularemia, and its virulence and infectiousness make it a potential agent of bioterrorism. previous studies using mononuclear leukocytes have shown that the lipopolysaccharide (lps) of f. tularensis is neither a typical proinflammatory endotoxin nor an endotoxin antagonist. this inertness suggests that f. tularensis lps does not bind host lps-sensing molecules such as lps-binding protein (lbp). using priming of t ... | 2006 | 16714555 |
| toll-like receptor 2 is required for control of pulmonary infection with francisella tularensis. | toll-like receptor 2 (tlr2) deficiency enhances murine susceptibility to infection by francisella tularensis as indicated by accelerated mortality, higher bacterial burden, and greater histopathology. analysis of pulmonary cytokine levels revealed that tlr2 deficiency results in significantly lower levels of tumor necrosis factor alpha and interleukin-6 but increased amounts of gamma interferon and monocyte chemoattractant protein 1. this pattern of cytokine production may contribute to the exag ... | 2006 | 16714598 |
| louse-borne bacterial pathogens in lice (phthiraptera) of rodents and cattle from egypt. | we collected 1,023 lice, representing 5 species, from rats and domestic cattle throughout 13 governorates in egypt and tested these lice for anaplasma marginale, bartonella spp., brucella spp., borrelia recurrentis, coxiella burnetii, francisella tularensis, and rickettsia spp. by pcr amplification and sequencing. five different louse-borne bacterial agents were detected in lice from rodents or cattle, including "bartonella rattimassiliensis", "b. phoceensis", and bartonella sp. near bartonella ... | 2006 | 16729688 |
| in vivo proteomic analysis of the intracellular bacterial pathogen, francisella tularensis, isolated from mouse spleen. | understanding the pathogenesis of infectious diseases requires comprehensive knowledge of the proteins expressed by the pathogen during in vivo growth in the host. proteomics provides the tools for such analyses but the protocols required to purify sufficient quantities of the pathogen from the host organism are currently lacking. here, we present a rapid immunomagnetic protocol for the separation of francisella tularensis, a highly virulent bacterium and potential biowarfare agent, from the spl ... | 2006 | 16730660 |
| characterization of the lipopolysaccharide and beta-glucan of the fish pathogen francisella victoria. | lipopolysaccharide (lps) and beta-glucan from francisella victoria, a fish pathogen and close relative of highly virulent mammal pathogen francisella tularensis, have been analyzed using chemical and spectroscopy methods. the polysaccharide part of the lps was found to contain a nonrepetitive sequence of 20 monosaccharides as well as alanine, 3-aminobutyric acid, and a novel branched amino acid, thus confirming f. victoria as a unique species. the structure identified composes the largest oligos ... | 2006 | 16759227 |
| tularemia: current epidemiology and disease management. | 2006 | 16762740 | |
| intracellular survival mechanisms of francisella tularensis, a stealth pathogen. | research on the highly virulent and contagious, facultative intracellular bacterium francisella tularensis has come into the limelight recently, but still little is known regarding its virulence mechanisms. this review summarizes recent studies on its intramacrophage survival mechanisms, some of which appear to be novel. | 2006 | 16239121 |
| francisella tularensis travels a novel, twisted road within macrophages. | francisella tularensis is a highly infectious intracellular bacterium that causes fulminating disease and is a potential bioweapon. although entry of the bacteria into macrophages is mediated by novel asymmetric, spacious pseudopod loops, the nascent phagosome becomes tight fitting within seconds of formation. biogenesis of the francisella-containing phagosome (fcp) is arrested for 2-4h at a unique stage within the endosomal-lysosomal degradation pathway, followed by gradual bacterial escape int ... | 2006 | 16356719 |