expression of fas receptor on human t lymphocytes under stimulation with borrelia burgdorferi sensu lato - preliminary results.apoptosis of activated t lymphocytes is essential to immunoregulation and its abnormalities have been observed in immune system disorders and persistent infections. to asses borrelia burgdorferi influence on the susceptibility of t lymphocytes to apoptosis, we have measured expression of the fas death receptor on these cells after incubation with live b. burgdorferi.201020639186
structure and immunomodulatory property relationship in napa of borrelia burgdorferi.napa from borrelia burgdorferi is a member of the dps-like protein family with specific immunomodulatory properties; in particular, napa is able to induce the expression of il-23 in neutrophils and monocytes, as well as the expression of il-6, il-1β, and transforming growth factor beta (tgf-β) in monocytes, via toll-like receptor (tlr) 2. such an activity on innate immune cells triggers a synovial fluid th17 response. here we report the crystal structure of napa, determined at 2.6å resolution, w ...201020851780
characterization of nicotinamidases: steady state kinetic parameters, classwide inhibition by nicotinaldehydes, and catalytic mechanism.nicotinamidases are metabolic enzymes that hydrolyze nicotinamide to nicotinic acid. these enzymes are widely distributed across biology, with examples found encoded in the genomes of mycobacteria, archaea, eubacteria, protozoa, yeast, and invertebrates, but there are none found in mammals. although recent structural work has improved our understanding of these enzymes, their catalytic mechanism is still not well understood. recent data show that nicotinamidases are required for the growth and v ...201020979384
structural determinants of inhibitor selectivity in prokaryotic imp dehydrogenases.the protozoan parasite cryptosporidium parvum is a major cause of gastrointestinal disease; no effective drug therapy exists to treat this infection. curiously, c. parvum impdh (cpimpdh) is most closely related to prokaryotic impdhs, suggesting that the parasite obtained its impdh gene via horizontal transfer. we previously identified inhibitors of cpimpdh that do not inhibit human impdhs. here, we show that these compounds also inhibit impdhs from helicobacter pylori, borrelia burgdorferi, and ...201021035731
[diseases and pathogenic agents transmitted by ticks in switzerland].among the 20 tick species described in switzerland, ixodes ricinus, the most frequent one, is implicated in the transmission of pathogenic agents. lyme borreliosis and tick-borne encephalitis (tbe) are the major tick-borne diseases transmitted to human. presently 5 borrelia species, belonging to the group borrelia burgdorferi, are recognized as human pathogens. the risks of infection depend on the stage of the vector, the multiple hosts, the pathogenic agent, as well as human behavior in nature. ...201021089555
tick histamine release factor is critical for ixodes scapularis engorgement and transmission of the lyme disease agent.ticks are distributed worldwide and affect human and animal health by transmitting diverse infectious agents. effective vaccines against most tick-borne pathogens are not currently available. in this study, we characterized a tick histamine release factor (thrf) from ixodes scapularis and addressed the vaccine potential of this antigen in the context of tick engorgement and b. burgdorferi transmission. results from western blotting and quantitative reverse transcription-pcr showed that thrf is s ...201021124826
questing ticks in suburban forest are infected by at least six tick-borne pathogens.abstract the role of ixodes ricinus ticks in the transmission of pathogens of public health importance such as borrelia burgdorferi s.l. is widely recognized and is suspected in several emerging vector-borne pathogens in europe. here, we assess prevalence rates of several endemic and emerging zoonotic pathogens in tick populations in an area of high human population density in france, to contribute to a risk assessment for potential transmission to humans. pathogen prevalence rates were evaluate ...201021158500
genetic diversity of borrelia burgdorferi and detection of b. bissettii-like dna in serum of north-coastal california north america, lyme borreliosis (lb) is a tick-borne disease caused by infection with the spirochete borrelia burgdorferi. we studied the genetic diversity of lb spirochetes in north-coastal california residents. spirochete dna was detected in 23.7% (27/114) of the study subjects using a pcr protocol optimized for increased sensitivity in human sera. californians were most commonly infected with b. burgdorferi ospc genotype a, a globally widespread spirochete associated with high virulence in ...201021177909
lyme disease diagnosis and treatment: lessons from the aids epidemic.lyme disease is a controversial tick-borne illness that is estimated to be four times more common than aids in the united states. this paper outlines the challenges overcome in the healthcare response to human immunodeficiency virus (hiv) infection, the development of sensitive laboratory tests for the aids virus, and the promotion of long-term combination antimicrobial regimens to effectively treat hiv disease. we suggest that similar challenges need to be overcome before the chronic form of ly ...201021196901
[relapsing borrelioses fevers: forgotten and new ones].relapsing fever borrelioses are widely spread in the endemic regions of eurasia, africa, and america as before and account for significant morbidity and mortality; however, these infections have been recently underestimated. the pathogens of the fevers are the borrelia species transmitted by ticks of the ornithodoros genus; they genetically differ from the pathogens of lyme borreliosis--borrelia burgdorferi sensu lato transmitted by ixodes ticks. the species borrelia miyamotoi belongs to the gen ...201021381356
multilocus sequence typing implicates rodents as the main reservoir host of human-pathogenic borrelia garinii in japan.multilocus sequence typing of borrelia garinii isolates from humans and comparison with rodent and tick isolates were performed. fifty-nine isolates were divided into two phylogenetic groups, and an association was detected between clinical and rodent isolates, suggesting that, in japan, human-pathogenic b. garinii comes from rodents via ticks.201121411595
the expanding lyme borrelia complex--clinical significance of genomic species?ten years after the discovery of spirochaetes as agents of lyme disease in 1982 in the usa, three genomic species had diverged from the phenotypically heterogeneous strains of borrelia burgdorferi isolated in north america and europe: borrelia afzelii, b. burgdorferi sensu stricto (further b. burgdorferi), and borrelia garinii. whereas b. burgdorferi remained the only human pathogen in north america, all three species are aetiological agents of lyme borreliosis in europe. another seven genospeci ...201121414082
a prospective study on the role of cxcl13 in lyme neuroborreliosis.the definite diagnosis of acute lyme neuroborreliosis (lnb) requires detection of an increased borrelia burgdorferi-specific antibody index (ai). the b burgdorferi ai, however, is negative in up to 20% of patients with early lnb and can remain elevated for years after adequate therapy; both of these factors can make the diagnosis difficult. recent retrospective studies suggested the chemokine cxcl13 as a potential biomarker for lnb. to evaluate its diagnostic value, we conducted a prospective st ...201121422457
ixodes ricinus ticks (acari: ixodidae): vectors for lyme disease spirochetes in this study 1,868 questing ixodes ricinus ticks (nymphs and adults), collected in six sites from three counties--giurgiu, sibiu, and tulcea--in romania, were examined by polymerase chain reaction (pcr) followed by reverse line blot (rlb) for detection of borrelia burgdorferi sensu lato presence. the bacteria were found in 18% of the investigated ticks. the prevalence of infection did not differ significantly between nymphs (19.1%) and adults (15.4%). three b. burgdorferi s.l. genospecies were ...201121431930
infectivity of borrelia burgdorferi sensu lato is unaltered in c3-deficient mice.b. burgdorferi, b. afzelii, and b. bavariensis show resistance to mouse and human complement. b. garinii and b. valaisiana are sensitive to mouse and human complement. we evaluated whether the absence of c3 in mice influenced infectivity and pathogenicity of different borrelia species. c3 knockout mice (c3-/-) and syngeneic c57bl/6 wild-type (wt) mice were challenged with 5 different borrelia species. after 2 weeks, quantitative pcr (qpcr), culture, histopathology, and immunofluorescence were pe ...201121771533
analysis of borrelia burgdorferi surface proteins as determinants in establishing host cell interactions.borrelia burgdorferi infection causes lyme borreliosis in humans, a condition which can involve a systemic spread of the organism to colonize various tissues and organs. if the infection is left untreated by antimicrobials, it can lead to manifestations including, arthritis, carditis, and/or neurological problems. identification and characterization of b. burgdorferi outer membrane proteins that facilitate cellular attachment and invasion to establish infection continue to be investigated. in th ...201121747816
development of a baited oral vaccine for use in reservoir-targeted strategies against lyme disease.lyme disease is a major human health problem which continues to increase in incidence and geographic distribution. as a vector-borne zoonotic disease, lyme disease may be amenable to reservoir targeted strategies for control. we have previously reported that a vaccinia virus (vv) based vaccine expressing outer surface protein a (ospa) of borrelia burgdorferi, the causative agent of lyme disease, protects inbred strains of laboratory mice against infection by feeding ticks and clears the ticks of ...201121816190
severe orthostatic hypotension in a diabetic patient may not be due to diabetic autonomic neuropathy.this lesson describes an unusual case of a man who was recently diagnosed with type 1 diabetes and who presented with severe orthostatic hypotension. as his diabetes was recent in onset, well controlled, and he had no other signs of microvascular disease, other causes of orthostatic hypotension were sought. his serum and cerebrospinal fluid were strongly positive for borrelia burgdorferi igg, suggesting a diagnosis of lyme neuroborreliosis. autonomic instability in lyme, while rare, has been pre ...201121902089
canine serology as adjunct to human lyme disease better define areas of human lyme disease risk, we compared us surveillance data with published data on the seroprevalence of borrelia burgdorferi antibodies among domestic dogs. canine seroprevalence >5% was a sensitive but nonspecific marker of human risk, whereas seroprevalence <1% was associated with minimal risk for human infection.201121888800
Molting success of Ixodes scapularis varies among individual blood meal hosts and species.The blacklegged tick (Ixodes scapularis) is an important vector of emerging human pathogens. It has three blood-feeding stages, as follows: larva, nymph, and adult. Owing to inefficient transovarial transmission, at least for the Lyme disease agent (Borrelia burgdorferi), larval ticks rarely hatch infected, but they can acquire infection during their larval blood meal. Nymphal ticks are primarily responsible for transmitting pathogens to hosts, including humans. The transition from uninfected ho ...201121845946
whole-genome sequences of borrelia bissettii, borrelia valaisiana, and borrelia has been known for decades that human lyme disease is caused by the three spirochete species borrelia burgdorferi, borrelia afzelii, and borrelia garinii. recently, borrelia valaisiana, borrelia spielmanii, and borrelia bissettii have been associated with lyme disease. we report the complete genome sequences of b. valaisiana vs116, b. spielmanii a14s, and b. bissettii dn127.201222207749
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