| detection of relapsing fever spirochetes (borrelia hermsii and borrelia coriaceae) in free-ranging mule deer (odocoileus hemionus) from nevada, united states. | abstract surveillance of mule deer (odocoileus hemionus, rafinesque, 1917) populations for tick-borne diseases has helped define the distribution of these pathogens and their subsequent risk of transmission to humans and domestic animals. we surveyed three mule deer herds across the state of nevada for infection with relapsing fever borrelia spp. spirochetes. bacterial prevalence varied by the county where deer were sampled but borrelia spirochetes were detected in 7.7% of all deer sampled. in ... | 2011 | 21995265 |
| cotransmission of divergent relapsing fever spirochetes by artificially infected ornithodoros hermsi. | the soft tick ornithodoros hermsi, which ranges in specific arboreal zones of western north america, acts as a vector for the relapsing fever spirochete borrelia hermsii. two genomic groups (genomic group i [ggi] and ggii) of b. hermsii are differentiated by multilocus sequence typing yet are codistributed in much of the vector's range. to test whether the tick vector can be infected via immersion, noninfected, colony-derived o. hermsi larvae were exposed to reduced-humidity conditions before im ... | 2011 | 21965393 |
| Differential impact of Toll-like receptor signaling on distinct B cell subpopulations. | B cells exhibit a range of functional responses following TLR engagement including immunoglobulin and cytokine production, proliferation, antigen presentation and migration. However, B cell intrinsic TLR responses appear to be precisely programmed based upon the developmental stage of the cell. B cell subpopulations classified as innate immune cells including marginal zone and B-1 B cells exhibit robust responses to TLR stimulation. In contrast, activation of other B cell subsets is constrained ... | 2012 | 22201817 |
| Syphilis: using modern approaches to understand an old disease. | Syphilis is a fascinating and perplexing infection, with protean clinical manifestations and both diagnostic and management ambiguities. Treponema pallidum subsp. pallidum, the agent of syphilis, is challenging to study in part because it cannot be cultured or genetically manipulated. Here, we review recent progress in the application of modern molecular techniques to understanding the biological basis of this multistage disease and to the development of new tools for diagnosis, for predicting e ... | 2011 | 22133883 |
| programmed cell death 1 suppresses b-1b cell expansion and long-lived igg production in response to t cell-independent type 2 antigens. | b-1b cells play a key role in producing abs against t cell-independent type 2 ags. however, the factors regulating ab production by this unique b cell subset are not well understood. in this study, a detailed analysis of the b cell response to 2,4,6-trinitrophenol (tnp)-ficoll was performed using normal mice. tnp-ficoll delivered i.p. or i.v. induced rapid ag-specific b-1b cell activation, expansion, isotype switching, and plasmablast/plasma cell differentiation. ag-specific b-1b cell numbers pe ... | 2011 | 22003198 |
| Characteristics of Borrelia hermsii infection in human hematopoietic stem cell-engrafted mice mirror those of human relapsing fever. | Rodents are natural reservoirs for a variety of species of Borrelia that cause relapsing fever (RF) in humans. The murine model of this disease recapitulates many of the clinical manifestations of the human disease and has revealed that T cell-independent antibody responses are required to resolve the bacteremic episodes. However, it is not clear whether such protective humoral responses are mounted in humans. We examined Borrelia hermsii infection in human hematopoietic stem cell-engrafted nono ... | 2011 | 22143787 |
| Computational and Biochemical Analysis of the Xanthomonas Effector AvrBs2 and Its Role in the Modulation of Xanthomonas Type Three Effector Delivery. | Effectors of the bacterial type III secretion system provide invaluable molecular probes to elucidate the molecular mechanisms of plant immunity and pathogen virulence. In this report, we focus on the AvrBs2 effector protein from the bacterial pathogen Xanthomonas euvesicatoria (Xe), the causal agent of bacterial spot disease of tomato and pepper. Employing homology-based structural analysis, we generate a three-dimensional structural model for the AvrBs2 protein and identify catalytic sites in ... | 2011 | 22144898 |
| microbial antigenic variation mediated by homologous dna recombination. | pathogenic microorganisms employ numerous molecular strategies in order to delay or circumvent recognition by the immune system of their host. one of the most widely used strategies of immune evasion is antigenic variation, in which immunogenic molecules expressed on the surface of a microorganism are continuously modified. as a consequence, the host is forced to constantly adapt its humoral immune response against this pathogen. an antigenic change thus provides the microorganism with an opport ... | 2011 | 22212019 |
| marginal zone b-cells, a gatekeeper of innate immunity. | to maintain the integrity of an organism constantly challenged by pathogens, the immune system is endowed with a variety of cell types. b lymphocytes were initially thought to only play a role in the adaptive branch of immunity. however, a number of converging observations revealed that two b-cell subsets, marginal zone (mz) and b1 cells, exhibit unique developmental and functional characteristics, and can contribute to innate immune responses. in addition to their capacity to mount a local anti ... | 2011 | 22566852 |
| regulatory b cell (b10 cell) expansion during listeria infection governs innate and cellular immune responses in mice. | pathogens use numerous methods to subvert host immune responses, including the modulation of host il-10 production by diverse cell types. however, the b cell sources of il-10 and their overall influence on innate and cellular immune responses have not been well characterized during infections. using listeria as a model pathogen, infection drove the acute expansion of a small subset of regulatory b cells (b10 cells) that potently suppress inflammation and autoimmunity through the production of il ... | 2012 | 23275601 |
| regulatory b cell (b10 cell) expansion during listeria infection governs innate and cellular immune responses in mice. | pathogens use numerous methods to subvert host immune responses, including the modulation of host il-10 production by diverse cell types. however, the b cell sources of il-10 and their overall influence on innate and cellular immune responses have not been well characterized during infections. using listeria as a model pathogen, infection drove the acute expansion of a small subset of regulatory b cells (b10 cells) that potently suppress inflammation and autoimmunity through the production of il ... | 2012 | 23275601 |
| annotation of protein domains reveals remarkable conservation in the functional make up of proteomes across superkingdoms. | the functional repertoire of a cell is largely embodied in its proteome, the collection of proteins encoded in the genome of an organism. the molecular functions of proteins are the direct consequence of their structure and structure can be inferred from sequence using hidden markov models of structural recognition. here we analyze the functional annotation of protein domain structures in almost a thousand sequenced genomes, exploring the functional and structural diversity of proteomes. we find ... | 2011 | 24710297 |
| evolution of dna ligases of nucleo-cytoplasmic large dna viruses of eukaryotes: a case of hidden complexity. | eukaryotic nucleo-cytoplasmic large dna viruses (ncldv) encode most if not all of the enzymes involved in their dna replication. it has been inferred that genes for these enzymes were already present in the last common ancestor of the ncldv. however, the details of the evolution of these genes that bear on the complexity of the putative ancestral ncldv and on the evolutionary relationships between viruses and their hosts are not well understood. | 2009 | 20021668 |
| laboratory confirmation of lyme disease. | lyme disease can be confirmed in the laboratory by isolation or detection of its causative agent, a tick-borne spirochete borrelia burgdorferi, or by a diagnostic change in the titre of antibodies specific to the agent. b burgdorferi can be isolated and cultivated in barbour-stoenner-kelly ii medium. it can be detected by light microscopy in tissue sections or, rarely, in blood smears using various staining methods. there is interest in the development of alternative detection methods, including ... | 1991 | 22529712 |
| classification and evolutionary history of the single-strand annealing proteins, rect, redbeta, erf and rad52. | the dna single-strand annealing proteins (ssaps), such as rect, redbeta, erf and rad52, function in reca-dependent and reca-independent dna recombination pathways. recently, they have been shown to form similar helical quaternary superstructures. however, despite the functional similarities between these diverse ssaps, their actual evolutionary affinities are poorly understood. | 2002 | 11914131 |
| phase and antigenic variation in bacteria. | phase and antigenic variation result in a heterogenic phenotype of a clonal bacterial population, in which individual cells either express the phase-variable protein(s) or not, or express one of multiple antigenic forms of the protein, respectively. this form of regulation has been identified mainly, but by no means exclusively, for a wide variety of surface structures in animal pathogens and is implicated as a virulence strategy. this review provides an overview of the many bacterial proteins a ... | 2004 | 15258095 |
| glycolipids as immunostimulating agents. | the processing and presentation of lipid antigens by antigen presenting cells (apc) is important for defense against infection, tumor immunosurveillance, and autoimmunity. cd1, a family of cell surface glycoproteins, is responsible for the binding and presentation of lipid antigens to receptors expressed on the surface of t lymphocytes. among the several (glyco)lipids identified to cause t-cell stimulation in complex with cd1, alpha-galactosyl ceramide (alpha-galcer) is one of the most well stud ... | 2007 | 18006319 |
| glycolipids as immunostimulating agents. | the processing and presentation of lipid antigens by antigen presenting cells (apc) is important for defense against infection, tumor immunosurveillance, and autoimmunity. cd1, a family of cell surface glycoproteins, is responsible for the binding and presentation of lipid antigens to receptors expressed on the surface of t lymphocytes. among the several (glyco)lipids identified to cause t-cell stimulation in complex with cd1, alpha-galactosyl ceramide (alpha-galcer) is one of the most well stud ... | 2007 | 18006319 |
| functional representation of enzymes by specific peptides. | predicting the function of a protein from its sequence is a long-standing goal of bioinformatic research. while sequence similarity is the most popular tool used for this purpose, sequence motifs may also subserve this goal. here we develop a motif-based method consisting of applying an unsupervised motif extraction algorithm (mex) to all enzyme sequences, and filtering the results by the four-level classification hierarchy of the enzyme commission (ec). the resulting motifs serve as specific pe ... | 2007 | 17722976 |
| glycolipid ligands of invariant natural killer t cells as vaccine adjuvants. | invariant natural killer t (inkt) cells are a unique subset of t lymphocytes that recognize glycolipid antigens in the context of the antigen-presenting molecule cd1d. upon glycolipid antigen stimulation, inkt cells rapidly produce copious amounts of immunomodulatory cytokines, leading to potent activation of a variety of innate and adaptive immune cells. these immune-potentiating properties of inkt cells hold great promise for the development of vaccine adjuvants. this review aims to summarize ... | 2008 | 19053208 |
| a comparative approach to elucidate chloroplast genome replication. | electron microscopy analyses of replicating chloroplast molecules earlier predicted bidirectional cairns replication as the prevalent mechanism, perhaps followed by rounds of a rolling circle mechanism. this standard model is being challenged by the recent proposition of homologous recombination-mediated replication in chloroplasts. | 2009 | 19457260 |
| complement control protein factor h: the good, the bad, and the inadequate. | the complement system is an essential component of the innate immune system that participates in elimination of pathogens and altered host cells and comprises an essential link between the innate and adaptive immune system. soluble and membrane-bound complement regulators protect cells and tissues from unintended complement-mediated injury. complement factor h is a soluble complement regulator essential for controlling the alternative pathway in blood and on cell surfaces. normal recognition of ... | 2010 | 20580090 |
| a pattern analysis of gene conversion literature. | gene conversion is an important biological process that involves the transfer of genetic (sequence) information from one gene to another. this can have a variety of effects on an organism, both short-term and long-term and both positive and detrimental. in an effort to better understand this process, we searched through over 3,000 abstracts that contain research on gene conversions, tagging the important data and performing an analysis on what we extract. through this we established trends that ... | 2010 | 20148076 |
| a pattern analysis of gene conversion literature. | gene conversion is an important biological process that involves the transfer of genetic (sequence) information from one gene to another. this can have a variety of effects on an organism, both short-term and long-term and both positive and detrimental. in an effort to better understand this process, we searched through over 3,000 abstracts that contain research on gene conversions, tagging the important data and performing an analysis on what we extract. through this we established trends that ... | 2010 | 20148076 |
| comparative analyses imply that the enigmatic sigma factor 54 is a central controller of the bacterial exterior. | sigma-54 is a central regulator in many pathogenic bacteria and has been linked to a multitude of cellular processes like nitrogen assimilation and important functional traits such as motility, virulence, and biofilm formation. until now it has remained obscure whether these phenomena and the control by sigma-54 share an underlying theme. | 2011 | 21806785 |
| experimental infections of the reservoir species peromyscus leucopus with diverse strains of borrelia burgdorferi, a lyme disease agent. | the rodent peromyscus leucopus is a major natural reservoir for the lyme disease agent borrelia burgdorferi and a host for its vector ixodes scapularis. at various locations in northeastern united states 10 to 15 b. burgdorferi strains coexist at different prevalences in tick populations. we asked whether representative strains of high or low prevalence differed in their infections of p. leucopus. after 5 weeks of experimental infection of groups with each of 6 isolates, distributions and burden ... | 2012 | 23221801 |
| experimental and natural infections in myd88- and irak-4-deficient mice and humans. | most toll-like-receptors (tlrs) and interleukin-1 receptors (il-1rs) signal via myeloid differentiation primary response 88 (myd88) and interleukin-1 receptor-associated kinase 4 (irak-4). the combined roles of these two receptor families in the course of experimental infections have been assessed in myd88- and irak-4-deficient mice for almost fifteen years. these animals have been shown to be susceptible to 46 pathogens: 27 bacteria, eight viruses, seven parasites, and four fungi. humans with i ... | 2012 | 23255009 |
| endemic foci of the tick-borne relapsing fever spirochete borrelia crocidurae in mali, west africa, and the potential for human infection. | tick-borne relapsing fever spirochetes are maintained in endemic foci that involve a diversity of small mammals and argasid ticks in the genus ornithodoros. most epidemiological studies of tick-borne relapsing fever in west africa caused by borrelia crocidurae have been conducted in senegal. the risk for humans to acquire relapsing fever in mali is uncertain, as only a few human cases have been identified. given the high incidence of malaria in mali, and the potential to confuse the clinical dia ... | 2012 | 23209863 |
| zoonotic infections among employees from great smoky mountains and rocky mountain national parks, 2008-2009. | u.s. national park service employees may have prolonged exposure to wildlife and arthropods, placing them at increased risk of infection with endemic zoonoses. to evaluate possible zoonotic risks present at both great smoky mountains (grsm) and rocky mountain (romo) national parks, we assessed park employees for baseline seroprevalence to specific zoonotic pathogens, followed by evaluation of incident infections over a 1-year study period. park personnel showed evidence of prior infection with a ... | 2012 | 22835153 |
| genetics of borrelia burgdorferi. | the spirochetes in the borrelia burgdorferi sensu lato genospecies group cycle in nature between tick vectors and vertebrate hosts. the current assemblage of b. burgdorferi sensu lato, of which three species cause lyme disease in humans, originated from a rapid species radiation that occurred near the origin of the clade. all of these species share a unique genome structure that is highly segmented and predominantly composed of linear replicons. one of the circular plasmids is a prophage that ex ... | 2012 | 22974303 |
| ebfc (ybab) is a new type of bacterial nucleoid-associated protein and a global regulator of gene expression in the lyme disease spirochete. | nearly every known species of eubacteria encodes a homolog of the borrelia burgdorferi ebfc dna-binding protein. we now demonstrate that fluorescently tagged ebfc associates with b. burgdorferi nucleoids in vivo and that chromatin immunoprecipitation (chip) of wild-type ebfc showed it to bind in vivo to sites throughout the genome, two hallmarks of nucleoid-associated proteins. comparative rna sequencing (rna-seq) of a mutant b. burgdorferi strain that overexpresses ebfc indicated that approxima ... | 2012 | 22544270 |
| delays and diversions mark the development of b cell responses to borrelia burgdorferi infection. | b cell responses modulate disease during infection with borrelia burgdorferi, the causative agent of lyme disease, but are unable to clear the infection. previous studies have demonstrated that b. burgdorferi infection induces predominantly t-independent b cell responses, potentially explaining some of these findings. however, others have shown effects of t cells on the isotype profile and the magnitude of the b. burgdorferi-specific abs. this study aimed to further investigate the humoral respo ... | 2012 | 22547698 |
| structure of factor h-binding protein b (fhbb) of the periopathogen, treponema denticola: insights into progression of periodontal disease. | periodontitis is the most common disease of microbial etiology in humans. periopathogen survival is dependent upon evasion of complement-mediated destruction. treponema denticola, an important contributor to periodontitis, evades killing by the alternative complement cascade by binding factor h (fh) to its surface. bound fh is rapidly cleaved by the t. denticola protease, dentilisin. in this report, the structure of the t. denticola fh-binding protein, fhbb, was solved to 1.7 å resolution. fhbb ... | 2012 | 22371503 |
| first isolation of the relapsing fever spirochete, borrelia hermsii, from a domestic dog. | in north america, tick-borne relapsing fever of humans is most frequently caused by infection with the spirochete borrelia hermsii. prior to our investigation, this spirochete was not known to infect dogs although another species, borrelia turicatae, has been isolated from domestic canids in florida and texas. a clinically ill dog in washington, usa, was spirochetemic upon examination. spirochetes were isolated from the dog's serum and examined by pcr and multi-locus sequence typing. dna sequenc ... | 2013 | 24252262 |
| first isolation of the relapsing fever spirochete, borrelia hermsii, from a domestic dog. | in north america, tick-borne relapsing fever of humans is most frequently caused by infection with the spirochete borrelia hermsii. prior to our investigation, this spirochete was not known to infect dogs although another species, borrelia turicatae, has been isolated from domestic canids in florida and texas. a clinically ill dog in washington, usa, was spirochetemic upon examination. spirochetes were isolated from the dog's serum and examined by pcr and multi-locus sequence typing. dna sequenc ... | 2013 | 24252262 |
| development of genetic system to inactivate a borrelia turicatae surface protein selectively produced within the salivary glands of the arthropod vector. | borrelia turicatae, an agent of tick-borne relapsing fever, is an example of a pathogen that can adapt to disparate conditions found when colonizing the mammalian host and arthropod vector. however, little is known about the genetic factors necessary during the tick-mammalian infectious cycle, therefore we developed a genetic system to transform this species of spirochete. we also identified a plasmid gene that was up-regulated in vitro when b. turicatae was grown in conditions mimicking the tic ... | 2013 | 24205425 |
| current status of syphilis vaccine development: need, challenges, prospects. | syphilis is a multistage disease caused by the invasive spirochete treponema pallidum subsp. pallidum. despite inexpensive and effective antibiotic therapy, syphilis remains a prevalent disease in developing countries and has re-emerged as a public health threat in developed nations. in addition to the medical burden imparted by infectious syphilis, congenital syphilis is considered the most significant infectious disease affecting fetuses and newborns worldwide, and individuals afflicted with s ... | 2013 | 24135571 |
| current status of syphilis vaccine development: need, challenges, prospects. | syphilis is a multistage disease caused by the invasive spirochete treponema pallidum subsp. pallidum. despite inexpensive and effective antibiotic therapy, syphilis remains a prevalent disease in developing countries and has re-emerged as a public health threat in developed nations. in addition to the medical burden imparted by infectious syphilis, congenital syphilis is considered the most significant infectious disease affecting fetuses and newborns worldwide, and individuals afflicted with s ... | 2013 | 24135571 |
| inter- and intra-specific pan-genomes of borrelia burgdorferi sensu lato: genome stability and adaptive radiation. | lyme disease is caused by spirochete bacteria from the borrelia burgdorferi sensu lato (b. burgdorferi s.l.) species complex. to reconstruct the evolution of b. burgdorferi s.l. and identify the genomic basis of its human virulence, we compared the genomes of 23 b. burgdorferi s.l. isolates from europe and the united states, including b. burgdorferi sensu stricto (b. burgdorferi s.s., 14 isolates), b. afzelii (2), b. garinii (2), b. "bavariensis" (1), b. spielmanii (1), b. valaisiana (1), b. bis ... | 2013 | 24112474 |
| chromosome sequence of borrelia miyamotoi, an uncultivable tick-borne agent of human infection. | borrelia miyamotoi is a newly recognized agent of human disease. b. miyamotoi strain lb-2001, an isolate from the tick ixodes scapularis, was propagated in mice. the sequence of the chromosome was determined by next-generation sequencing of dna isolated from whole blood. the sequence established that b. miyamotoi is a relapsing fever group species. | 2013 | 24029760 |
| transport of ixodid ticks and tick-borne pathogens by migratory birds. | birds, particularly passerines, can be parasitized by ixodid ticks, which may be infected with tick-borne pathogens, like borrelia spp., babesia spp., anaplasma, rickettsia/coxiella, and tick-borne encephalitis virus. the prevalence of ticks on birds varies over years, season, locality and different bird species. the prevalence of ticks on different species depends mainly on the degree of feeding on the ground. in europe, the turdus spp., especially the blackbird, turdus merula, appears to be mo ... | 2013 | 24058903 |
| a guide to utilization of the microbiology laboratory for diagnosis of infectious diseases: 2013 recommendations by the infectious diseases society of america (idsa) and the american society for microbiology (asm)(a). | the critical role of the microbiology laboratory in infectious disease diagnosis calls for a close, positive working relationship between the physician and the microbiologists who provide enormous value to the health care team. this document, developed by both laboratory and clinical experts, provides information on which tests are valuable and in which contexts, and on tests that add little or no value for diagnostic decisions. sections are divided into anatomic systems, including bloodstream i ... | 2013 | 23845951 |
| bb0172, a borrelia burgdorferi outer membrane protein that binds integrin α3β1. | lyme disease is a multisystemic disorder caused by borrelia burgdorferi infection. upon infection, some b. burgdorferi genes are upregulated, including members of the microbial surface components recognizing adhesive matrix molecule (mscramm) protein family, which facilitate b. burgdorferi adherence to extracellular matrix components of the host. comparative genome analysis has revealed a new family of b. burgdorferi proteins containing the von willebrand factor a (vwfa) domain. in the present s ... | 2013 | 23687274 |
| a phylogenomic and molecular signature based approach for characterization of the phylum spirochaetes and its major clades: proposal for a taxonomic revision of the phylum. | the spirochaetes species cause many important diseases including syphilis and lyme disease. except for their containing a distinctive endoflagella, no other molecular or biochemical characteristics are presently known that are specific for either all spirochaetes or its different families. we report detailed comparative and phylogenomic analyses of protein sequences from spirochaetes genomes to understand their evolutionary relationships and to identify molecular signatures for this group. these ... | 2013 | 23908650 |
| mapping the ligand-binding region of borrelia hermsii fibronectin-binding protein. | many pathogenic microorganisms express fibronectin-binding molecules that facilitate their adherence to the extracellular matrix and/or entry into mammalian cells. we have previously described a borrelia recurrentis gene, cihc that encodes a 40-kda surface receptor for both, fibronectin and the complement inhibitors c4bp and c1-inh. we now provide evidence for the expression of a group of highly homologues surface proteins, termed fbpa, in three b. hermsii isolates and two tick-borne relapsing f ... | 2013 | 23658828 |
| microbes bind complement inhibitor factor h via a common site. | to cause infections microbes need to evade host defense systems, one of these being the evolutionarily old and important arm of innate immunity, the alternative pathway of complement. it can attack all kinds of targets and is tightly controlled in plasma and on host cells by plasma complement regulator factor h (fh). fh binds simultaneously to host cell surface structures such as heparin or glycosaminoglycans via domain 20 and to the main complement opsonin c3b via domain 19. many pathogenic mic ... | 2013 | 23637600 |
| the htra protease of borrelia burgdorferi degrades outer membrane protein bmpd and chemotaxis phosphatase chex. | borrelia burgdorferi, the spirochaetal agent of lyme disease, codes for a single htra protein, htrabb (bb0104) that is homologous to degp of escherichia coli (41% amino acid identity). htrabb shows physical and biochemical similarities to degp in that it has the trimer as its fundamental unit and can degrade casein via its catalytic serine. recombinant htrabb exhibits proteolytic activity in vitro, while a mutant (htrabbs198a) does not. however, htrabb and degp have some important differences as ... | 2013 | 23565798 |
| what is the risk for exposure to vector-borne pathogens in united states national parks? | united states national parks attract > 275 million visitors annually and collectively present risk of exposure for staff and visitors to a wide range of arthropod vector species (most notably fleas, mosquitoes, and ticks) and their associated bacterial, protozoan, or viral pathogens. we assessed the current state of knowledge for risk of exposure to vector-borne pathogens in national parks through a review of relevant literature, including internal national park service documents and organismal ... | 2013 | 23540107 |
| improved culture conditions for the growth and detection of borrelia from human serum. | in this report we present a method to cultivate borrelia spirochetes from human serum samples with high efficiency. this method incorporates improved sample collection, optimization of culture media and use of matrix protein. the method was first optimized utilizing borrelia laboratory strains, and later by demonstrating growth of borrelia from sera from fifty seropositive lyme disease patients followed by another cohort of 72 lyme disease patients, all of whom satisfied the strict cdc surveilla ... | 2013 | 23470960 |
| multiplex real-time pcr diagnostic of relapsing fevers in africa. | in africa, relapsing fever borreliae are neglected arthropod-borne pathogens causing mild to deadly septicemia and miscarriage. the closely related borrelia crocidurae, borrelia duttonii, borrelia recurrentis and borrelia hispanica are rarely diagnosed at the species level, hampering refined epidemiological and clinical knowledge of the relapsing fevers. it would be hugely beneficial to have simultaneous detection and identification of borrelia to species level directly from clinical samples. | 2013 | 23390560 |
| the western progression of lyme disease: infectious and nonclonal borrelia burgdorferi sensu lato populations in grand forks county, north dakota. | scant attention has been paid to lyme disease, borrelia burgdorferi, ixodes scapularis, or reservoirs in eastern north dakota despite the fact that it borders high-risk counties in minnesota. recent reports of b. burgdorferi and i. scapularis in north dakota, however, prompted a more detailed examination. spirochetes cultured from the hearts of five rodents trapped in grand forks county, nd, were identified as b. burgdorferi sensu lato through sequence analyses of the 16s rrna gene, the 16s rrna ... | 2014 | 25304515 |
| the western progression of lyme disease: infectious and nonclonal borrelia burgdorferi sensu lato populations in grand forks county, north dakota. | scant attention has been paid to lyme disease, borrelia burgdorferi, ixodes scapularis, or reservoirs in eastern north dakota despite the fact that it borders high-risk counties in minnesota. recent reports of b. burgdorferi and i. scapularis in north dakota, however, prompted a more detailed examination. spirochetes cultured from the hearts of five rodents trapped in grand forks county, nd, were identified as b. burgdorferi sensu lato through sequence analyses of the 16s rrna gene, the 16s rrna ... | 2014 | 25304515 |
| antigenic variation of tprk facilitates development of secondary syphilis. | although primary syphilis lesions heal spontaneously, the infection is chronic, with subsequent clinical stages. healing of the primary chancre occurs as antibodies against outer membrane antigens facilitate opsonophagocytosis of the bacteria by activated macrophages. tprk is an outer membrane protein that undergoes antigenic variation at 7 variable regions, and variants are selected by immune pressure. we hypothesized that individual tprk variants escape immune clearance and seed new disseminat ... | 2014 | 25225245 |
| high seroprevalence of borrelia miyamotoi antibodies in forestry workers and individuals suspected of human granulocytic anaplasmosis in the netherlands. | substantial exposure to borrelia miyamotoi occurs through bites from ixodes ricinus ticks in the netherlands, which also transmit borrelia burgdorferi sensu lato and anaplasma phagocytophilum. direct evidence for b. miyamotoi infection in european populations is scarce. a flu-like illness with high fever, resembling human granulocytic anaplasmosis, has been attributed to b. miyamotoi infections in relatively small groups. borrelia miyamotoi infections associated with chronic meningoencephalitis ... | 2014 | 25356364 |
| molecular typing of borrelia burgdorferi. | borrelia burgdorferi sensu lato is a group of spirochetes belonging to the genus borrelia in the family of spirochaetaceae. the spirochete is transmitted between reservoirs and hosts by ticks of the family ixodidae. infection with b. burgdorferi in humans causes lyme disease or lyme borreliosis. currently, 20 lyme disease-associated borrelia species and more than 20 relapsing fever-associated borrelia species have been described. identification and differentiation of different borrelia species a ... | 2014 | 25082003 |
| the borrelia hermsii factor h binding protein fhba is not required for infectivity in mice or for resistance to human complement in vitro. | the primary causative agent of tick-borne relapsing fever in north america is borrelia hermsii. it has been hypothesized that b. hermsii evades complement-mediated destruction by binding factor h (fh), a host-derived negative regulator of complement. in vitro, b. hermsii produces a single fh binding protein designated fhba (fh binding protein a). the properties and ligand binding activity of fhba suggest that it plays multiple roles in pathogenesis. it binds plasminogen and has been identified a ... | 2014 | 24866803 |
| construction and characterization of a borrelia burgdorferi strain with conditional expression of the essential telomere resolvase, rest. | borrelia species are unique in the bacterial world in possessing segmented genomes which sometimes contain over 20 genetic elements. most elements are linear and contain covalently closed hairpin ends requiring a specialized process, telomere resolution, for their generation. hairpin telomere resolution is mediated by the telomere resolvase, rest. although the process has been studied extensively in vitro, the essential nature of the rest gene has precluded biological studies to further probe th ... | 2014 | 24748617 |
| african relapsing fever borreliae genomospecies revealed by comparative genomics. | relapsing fever borreliae are vector-borne bacteria responsible for febrile infection in humans in north america, africa, asia, and in the iberian peninsula in europe. relapsing fever borreliae are phylogenetically closely related, yet they differ in pathogenicity and vectors. their long-term taxonomy, based on geography and vector grouping, needs to be re-apprised in a genomic context. we therefore embarked into genomic analyses of relapsing fever borreliae, focusing on species found in africa. | 2014 | 25229054 |
| inactivation of genes for antigenic variation in the relapsing fever spirochete borrelia hermsii reduces infectivity in mice and transmission by ticks. | borrelia hermsii, a causative agent of relapsing fever of humans in western north america, is maintained in enzootic cycles that include small mammals and the tick vector ornithodoros hermsi. in mammals, the spirochetes repeatedly evade the host's acquired immune response by undergoing antigenic variation of the variable major proteins (vmps) produced on their outer surface. this mechanism prolongs spirochete circulation in blood, which increases the potential for acquisition by fast-feeding tic ... | 2014 | 24699793 |
| transmission dynamics of borrelia turicatae from the arthropod vector. | with the global distribution, morbidity, and mortality associated with tick and louse-borne relapsing fever spirochetes, it is important to understand the dynamics of vector colonization by the bacteria and transmission to the host. tick-borne relapsing fever spirochetes are blood-borne pathogens transmitted through the saliva of soft ticks, yet little is known about the transmission capability of these pathogens during the relatively short bloodmeal. this study was therefore initiated to unders ... | 2014 | 24699275 |
| detection of borrelia theileri in rhipicephalus geigyi from mali. | disease burden within cattle is a concern around the world. bovine borreliosis, one such disease, is caused by the spirochete borrelia theileri transmitted by the bite of an infected rhipicephalus (boophilus) species tick. a number of species within the genus are capable of transmitting the agent and are found on multiple continents. cattle in the west african nation of mali are infested with four species of rhipicephalus ticks of the subgenus boophilus: rhipicephalus annulatus, rhipicephalus mi ... | 2014 | 24709337 |
| identification of borrelia species after creation of an in-house maldi-tof ms database. | lyme borreliosis (lb) is a multisystemic disease caused by borrelia burgdorferi sensu lato (sl) complex transmitted to humans by ixodes ticks. b. burgdorferi sl complex, currently comprising at least 19 genospecies, includes the main pathogenic species responsible for human disease in europe: b. burgdorferi sensu stricto (ss), b. afzelii, and b. garinii. in this study, for the first time, maldi-tof ms was applied to borrelia spp., supplementing the existing database, limited to the species b. bu ... | 2014 | 24533160 |
| tick-borne relapsing fever in pregnancy. | | 2014 | 23939208 |
| laboratory diagnosis of tick-borne african relapsing fevers: latest developments. | in africa, relapsing fevers caused by ectoparasite-borne borrelia species are transmitted by ticks, with the exception of borrelia recurrentis, which is a louse-borne spirochete. these tropical diseases are responsible for mild to deadly spirochetemia. cultured borrelia crocidurae, borrelia duttonii, and borrelia hispanica circulate alongside at least six species that have not yet been cultured in vectors. direct diagnosis is hindered by the use of non-specific laboratory tools. indeed, microsco ... | 2015 | 26618151 |
| spirochetal motility and chemotaxis in the natural enzootic cycle and development of lyme disease. | two-thirds of all bacterial genomes sequenced to-date possess an organelle for locomotion, referred to as flagella, periplasmic flagella or type iv pili. these genomes may also contain a chemotaxis-signaling system which governs flagellar rotation, thus leading a coordinated function for motility. motility and chemotaxis are often crucial for infection or disease process caused by pathogenic bacteria. although motility-associated genes are well-characterized in some organisms, the highly orchest ... | 2015 | 26519910 |
| vaccination with the variable tick protein of the relapsing fever spirochete borrelia hermsii protects mice from infection by tick-bite. | tick-borne relapsing fevers of humans are caused by spirochetes that must adapt to both warm-blooded vertebrates and cold-blooded ticks. in western north america, most human cases of relapsing fever are caused by borrelia hermsii, which cycles in nature between its tick vector ornithodoros hermsi and small mammals such as tree squirrels and chipmunks. these spirochetes alter their outer surface by switching off one of the bloodstream-associated variable major proteins (vmps) they produce in mamm ... | 2015 | 26490040 |
| ixodes ricinus and its endosymbiont midichloria mitochondrii: a comparative proteomic analysis of salivary glands and ovaries. | hard ticks are hematophagous arthropods that act as vectors of numerous pathogenic microorganisms of high relevance in human and veterinary medicine. ixodes ricinus is one of the most important tick species in europe, due to its role of vector of pathogenic bacteria such as borrelia burgdorferi and anaplasma phagocytophilum, of viruses such as tick borne encephalitis virus and of protozoans as babesia spp. in addition to these pathogens, i. ricinus harbors a symbiotic bacterium, midichloria mito ... | 2015 | 26398775 |
| borrelia burgdorferi elongation factor ef-tu is an immunogenic protein during lyme borreliosis. | borrelia burgdorferi, the etiological agent of lyme disease, does not produce lipopolysaccharide but expresses a large number of lipoproteins on its cell surface. these outer membrane lipoproteins are highly immunogenic and have been used for serodiagnosis of lyme disease. recent studies have shown that highly conserved cytosolic proteins such as enolase and elongation factor tu (ef-tu) unexpectedly localized on the surface of bacteria including b. burgdorferi, and surface-localized enolase has ... | 2015 | 26954993 |
| mini-review: strategies for variation and evolution of bacterial antigens. | across the eubacteria, antigenic variation has emerged as a strategy to evade host immunity. however, phenotypic variation in some of these antigens also allows the bacteria to exploit variable host niches as well. the specific mechanisms are not shared-derived characters although there is considerable convergent evolution and numerous commonalities reflecting considerations of natural selection and biochemical restraints. unlike in viruses, mechanisms of antigenic variation in most bacteria inv ... | 2015 | 26288700 |
| major emerging vector-borne zoonotic diseases of public health importance in canada. | in canada, the emergence of vector-borne diseases may occur via international movement and subsequent establishment of vectors and pathogens, or via northward spread from endemic areas in the usa. re-emergence of endemic vector-borne diseases may occur due to climate-driven changes to their geographic range and ecology. lyme disease, west nile virus (wnv), and other vector-borne diseases were identified as priority emerging non-enteric zoonoses in canada in a prioritization exercise conducted by ... | 2015 | 26954882 |
| strategies and approaches in plasmidome studies-uncovering plasmid diversity disregarding of linear elements? | the term plasmid was originally coined for circular, extrachromosomal genetic elements. today, plasmids are widely recognized not only as important factors facilitating genome restructuring but also as vehicles for the dissemination of beneficial characters within bacterial communities. plasmid diversity has been uncovered by means of culture-dependent or -independent approaches, such as endogenous or exogenous plasmid isolation as well as pcr-based detection or transposon-aided capture, respect ... | 2015 | 26074886 |
| mutations in the borrelia burgdorferi flagellar type iii secretion system genes flih and flii profoundly affect spirochete flagellar assembly, morphology, motility, structure, and cell division. | the lyme disease spirochete borrelia burgdorferi migrates to distant sites in the tick vectors and mammalian hosts through robust motility and chemotaxis activities. flih and flii are two cytoplasmic proteins that play important roles in the type iii secretion system (t3ss)-mediated export and assembly of flagellar structural proteins. however, detailed analyses of the roles of flih and flii in b. burgdorferi have not been reported. in this study, flih and flii transposon mutants were utilized t ... | 2015 | 25968649 |
| broad diversity of host responses of the white-footed mouse peromyscus leucopus to borrelia infection and antigens. | peromyscus leucopus, the white-footed mouse, is one of the more abundant mammals of north america and is a major reservoir host for at least five tickborne diseases of humans, including lyme disease and a newly-recognized form of relapsing fever. in comparison to mus musculus, which is not a natural reservoir for any of these infections, there has been little research on experimental infections in p. leucopus. with the aim of further characterizing the diversity of phenotypes of host responses, ... | 2015 | 26005106 |
| tick microbiome: the force within. | ticks are obligate blood-feeders and serve as vectors of human and livestock pathogens worldwide. defining the tick microbiome and deciphering the interactions between the tick and its symbiotic bacteria in the context of tick development and pathogen transmission will likely reveal new insights and spawn new paradigms to control tick-borne diseases. descriptive observations on the tick microbiome that began almost a century ago serve as forerunners to the gathering momentum to define the tick m ... | 2015 | 25936226 |
| case report: a retrospective serological analysis indicating human exposure to tick-borne relapsing fever spirochetes in texas. | | 2015 | 25856342 |
| isolation and characterization of borrelia burgdorferi strains from ixodes ricinus ticks in the southern england. | lyme disease is a bacterial infection caused by the spiral-shaped bacterium borrelia burgdorferi. we investigated the presence and prevalence of borrelia species in ticks from the southern england. | 2015 | 26191500 |
| current and past strategies for bacterial culture in clinical microbiology. | a pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the understanding and treatment of caused diseases. the first culture conditions empirically varied incubation time, nutrients, atmosphere, and temperature; culture was then gradually abandoned in favor of molecular methods. the rebirth of culture in clinical microbiology was prompted by microbiologists specializing in intracellular bacteria. th ... | 2015 | 25567228 |
| host associations and genomic diversity of borrelia hermsii in an endemic focus of tick-borne relapsing fever in western north america. | an unrecognized focus of tick-borne relapsing fever caused by borrelia hermsii was identified in 2002 when five people became infected on wild horse island in flathead lake, montana. the terrestrial small mammal community on the island is composed primarily of pine squirrels (tamiasciurus hudsonicus) and deer mice (peromyscus maniculatus), neither of which was known as a natural host for the spirochete. thus a 3-year study was performed to identify small mammals as hosts for b. hermsii. | 2016 | 27832805 |
| multifunctional and redundant roles of borrelia burgdorferi outer surface proteins in tissue adhesion, colonization, and complement evasion. | borrelia burgdorferi is the causative agent of lyme disease in the u.s., with at least 25,000 cases reported to the cdc each year. b. burgdorferi is thought to enter and exit the bloodstream to achieve rapid dissemination to distal tissue sites during infection. travel through the bloodstream requires evasion of immune surveillance and pathogen clearance in the host, a process at which b. burgdorferi is adept. b. burgdorferi encodes greater than 19 adhesive outer surface proteins many of which h ... | 2016 | 27818662 |
| morgellons disease: a filamentous borrelial dermatitis. | morgellons disease (md) is a dermopathy characterized by multicolored filaments that lie under, are embedded in, or project from skin. although md was initially considered to be a delusional disorder, recent studies have demonstrated that the dermopathy is associated with tickborne infection, that the filaments are composed of keratin and collagen, and that they result from proliferation of keratinocytes and fibroblasts in epithelial tissue. culture, histopathological and molecular evidence of s ... | 2016 | 27789971 |
| close encounters of lymphoid cells and bacteria. | during infections, the first reaction of the host against microbial pathogens is carried out by innate immune cells, which recognize conserved structures on pathogens, called pathogen-associated molecular patterns. afterward, some of these innate cells can phagocytose and destroy the pathogens, secreting cytokines that would modulate the immune response to the challenge. this rapid response is normally followed by the adaptive immunity, more specific and essential for a complete pathogen clearan ... | 2016 | 27774092 |
| b-1 cell heterogeneity and the regulation of natural and antigen-induced igm production. | a small subset of b cells, termed b-1 cells, with developmental origins, phenotypes, and functions that are distinct from those of conventional b cells exist in mice. it contributes the vast majority of spontaneously produced "natural" igm. natural igm is constitutively produced, even in the absence of microbiota, and fulfills many distinct functions in tissue homeostasis and host defense. b-1 cells also respond with igm production to innate signals and pathogen exposure, while maintaining stead ... | 2016 | 27667991 |
| borrelia miyamotoi infection in patients from upper midwestern united states, 2014-2015. | we confirmed borrelia miyamotoi infection in 7 patients who had contracted an illness while near la crosse, wisconsin, usa, an area where ixodes scapularis ticks are endemic. b. miyamatoi infection should now be considered among differential diagnoses for patients from the midwestern united states who have signs and symptoms suggestive of tickborne illness. | 2016 | 27434048 |
| consensus computational network analysis for identifying candidate outer membrane proteins from borrelia spirochetes. | similar to gram-negative organisms, borrelia spirochetes are dual-membrane organisms with both an inner and outer membrane. although the outer membrane contains integral membrane proteins, few of the borrelial outer membrane proteins (omps) have been identified and characterized to date. therefore, we utilized a consensus computational network analysis to identify novel borrelial omps. | 2016 | 27400788 |
| comparative genomics reveals multiple pathways to mutualism for tick-borne pathogens. | multiple important human and livestock pathogens employ ticks as their primary host vectors. it is not currently known whether this means of infecting a host arose once or many times during evolution. | 2016 | 27368698 |
| tick-borne relapsing fever in dogs. | in the united states, tick-borne relapsing fever (tbrf) in dogs is caused by the spirochete bacteria borrelia turicatae and borrelia hermsii, transmitted by ornithodoros spp. ticks. the hallmark diagnostic feature of this infection is the visualization of numerous spirochetes during standard blood smear examination. although the course of spirochetemia has not been fully characterized in dogs, in humans infected with tbrf the episodes of spirochetemia and fever are intermittent. | 2016 | 27353196 |
| novel borrelia species detected in echidna ticks, bothriocroton concolor, in australia. | to date, little has been documented about microorganisms harboured within australian native ticks or their pathogenic potential. recently, a borrelia sp. related to the relapsing fever (rf) group was identified in a single tick removed from a wild echidna (tachyglossus aculeatus). the present study investigated the presence of borrelia in 97 bothriocroton concolor ticks parasitizing echidnas in queensland, new south wales, and victoria, australia, using nested pcr with borrelia-specific primers ... | 2016 | 27301754 |
| characterization of a dna adenine methyltransferase gene of borrelia hermsii and its dispensability for murine infection and persistence. | dna methyltransferases have been implicated in the regulation of virulence genes in a number of pathogens. relapsing fever borrelia species harbor a conserved, putative dna methyltransferase gene on their chromosome, while no such ortholog can be found in the annotated genome of the lyme disease agent, borrelia burgdorferi. in the relapsing fever species borrelia hermsii, the locus bh0463a encodes this putative dna adenine methyltransferase (dam). to verify the function of the bh0463a protein pr ... | 2016 | 27195796 |
| the borrelia burgdorferi telomere resolvase, rest, anneals ssdna complexed with its cognate ssdna-binding protein. | spirochetes of the genus borrelia possess unusual genomes that consist in a linear chromosome and multiple linear and circular plasmids. the linear replicons are terminated by covalently closed hairpin ends, referred to as hairpin telomeres. the hairpin telomeres represent a simple solution to the end-replication problem. deoxyribonucleic acid replication initiates internally and proceeds bidirectionally toward the hairpin telomeres. the telomere resolvase, rest, forms the hairpin telomeres from ... | 2016 | 27131360 |
| expression of the tick-associated vtp protein of borrelia hermsii in a murine model of relapsing fever. | borrelia hermsii, a spirochete and cause of relapsing fever, is notable for its immune evasion by multiphasic antigenic variation within its vertebrate host. this is based on a diverse repertoire of surface antigen genes, only one of which is expressed at a time. another major surface protein, the variable tick protein (vtp), is expressed in the tick vector and is invariable at its genetic locus. given the limited immune systems of ticks, the finding of considerable diversity among the vtp prote ... | 2016 | 26918760 |
| evidence of in vivo existence of borrelia biofilm in borrelial lymphocytomas. | lyme borreliosis, caused by the spirochete borrelia burgdorferi sensu lato, has grown into a major public health problem. we recently identified a novel morphological form of b. burgdorferi, called biofilm, a structure that is well known to be highly resistant to antibiotics. however, there is no evidence of the existence of borrelia biofilm in vivo; therefore, the main goal of this study was to determine the presence of borrelia biofilm in infected human skin tissues. archived skin biopsy tissu ... | 2016 | 27141311 |
| transcriptional profiling the 150 kb linear megaplasmid of borrelia turicatae suggests a role in vector colonization and initiating mammalian infection. | adaptation is key for survival as vector-borne pathogens transmit between the arthropod and vertebrate, and temperature change is an environmental signal inducing alterations in gene expression of tick-borne spirochetes. while plasmids are often associated with adaptation, complex genomes of relapsing fever spirochetes have hindered progress in understanding the mechanisms of vector colonization and transmission. we utilized recent advances in genome sequencing to generate the most complete vers ... | 2016 | 26845332 |
| antigenic variation in bacterial pathogens. | antigenic variation is a strategy used by a broad diversity of microbial pathogens to persist within the mammalian host. whereas viruses make use of a minimal proofreading capacity combined with large amounts of progeny to use random mutation for variant generation, antigenically variant bacteria have evolved mechanisms which use a stable genome, which aids in protecting the fitness of the progeny. here, three well-characterized and highly antigenically variant bacterial pathogens are discussed: ... | 2016 | 26999387 |
| monoclonal antibodies for the diagnosis of borrelia crocidurae. | relapsing fever borreliae, produced by ectoparasite-borne borrelia species, cause mild to deadly bacteremia and miscarriage. in the perspective of developing inexpensive assays for the rapid detection of relapsing fever borreliae, we produced 12 monoclonal antibodies (mabs) against borrelia crocidurae and characterized the two exhibiting the highest titers. p3a10 mab reacts with the 35.6-kda flagellin b (flab) of b. crocidurae while p6d9 mab recognizes a 35.1-kda variable-like protein (vlp) in b ... | 2016 | 26598566 |
| establishing goals, techniques and priorities for national communicable disease surveillance. | | 1991 | 22451750 |
| the ins and outs of dna fingerprinting the infectious fungi. | dna fingerprinting methods have evolved as major tools in fungal epidemiology. however, no single method has emerged as the method of choice, and some methods perform better than others at different levels of resolution. in this review, requirements for an effective dna fingerprinting method are proposed and procedures are described for testing the efficacy of a method. in light of the proposed requirements, the most common methods now being used to dna fingerprint the infectious fungi are descr ... | 2000 | 10756003 |
| a short guided tour through functional and structural features of saposin-like proteins. | saplips (saposin-like proteins) are a diverse family of lipid-interacting proteins that have various and only partly understood, but nevertheless essential, cellular functions. their existence is conserved in phylogenetically most distant organisms, such as primitive protozoa and mammals. owing to their remarkable sequence variability, a common mechanism for their actions is not known. some shared principles beyond their diversity have become evident by analysis of known three-dimensional struct ... | 2005 | 15992358 |
| host-parasite interactions and the evolution of gene expression. | interactions between hosts and parasites provide an ongoing source of selection that promotes the evolution of a variety of features in the interacting species. here, we use a genetically explicit mathematical model to explore how patterns of gene expression evolve at genetic loci responsible for host resistance and parasite infection. our results reveal the striking yet intuitive conclusion that gene expression should evolve along very different trajectories in the two interacting species. spec ... | 2005 | 15913420 |
| new feel for new phyla. | | 2008 | 18665943 |
| peripheral b cell subsets. | our understanding of the origins and the biological functions of different peripheral b cell subsets continues to evolve. some understanding has been obtained regarding the synergy between bcr-derived signals and other receptors and signaling pathways that drive the development of follicular, marginal zone, and b-1 b cells, but this remains a complex and poorly understood issue. more recent information regarding the origins of b-1 and b-2 b cells, the ability of follicular b cells to mature both ... | 2008 | 18434123 |