| neurosecretion in ornithodoros savignyi (audouin) (ixodoidea: argasidae). the distribution of neurosecretory cells in the brain. | the arrangement of the brain and peripheral nerves in ornithodoros savignyi (audouin) is similar to that of other argasid and ixodid ticks. histological studies, using a specialized staining technique (aldehyde fuchsin), have shown 15 groups of neurosecretory cells in the cortex of the brain. | 1977 | 614529 |
| proteins and free amino acids in the salivary secretion and haemolymph of the tick amblyomma hebraeum. | electrophoretic and chromatographic separations of the salivary secretion of amblyomma hebraeum showed a less complex protein pattern than that of ornithodoros savignyi. a hyaluronidase active component was isolated. the haemolymph protein pattern showed a major protein fraction with a mobility slightly faster than that of bovine serum albumin. | 1978 | 754123 |
| the identification of a shared immunogen present in the salivary glands and gut of ixodid and argasid ticks. | the identification of a 70-kda immunogen present in salivary gland extracts of several ixodid species, namely hyalomma truncatum (sweating-sickness-inducing (ss+) and non-inducing (ss-) strains), hyalomma marginatum rufipes and rhipicephalus evertsi evertsi, is reported. the immunogen was identified by western blots using a monoclonal antibody of the igm isotype directed against a 70-kda immunogen present in the salivary glands of (ss-) female h. truncatum ticks. cross-reactivity with the gut of ... | 1992 | 1446571 |
| experimental transmission of african swine fever virus by ornithodoros savignyi (audouin). | the 'sand tampan', ornithodoros savignyi, is susceptible to oral infection with african swine fever (asf) virus in the laboratory. infected ticks can transmit the virus transstadially and are able to maintain it for at least 106 days. transmission of asf virus by infected ticks to healthy pigs was achieved on five separate occasions between 50 and 106 days after infection. pigs infected in this way developed typical acute african swine fever. the distribution of o savignyi in africa suggests tha ... | 1985 | 4081341 |
| investigations into sex dimorphism during nuclear interphase of the argasid tick, ornithodoros savignyi (audouin, 1827). | | 1966 | 4165342 |
| on the evacuation of sperm from the spermatophore of the tick, ornithodoros savignyi. | | 1973 | 4774532 |
| chemical composition of the coxal fluid of the argasid tick ornithodoros savignyi. | | 1974 | 4850992 |
| effect of ronnel on the respiration rate of ornithodoros savignyi ticks at different temperatures after topical application or oral ingestion. | | 1971 | 5555012 |
| a rickettsialike microorganism in the tick ornithodoros savignyi: observations on its structure and distribution in the tissues of the tick. | | 1968 | 5672007 |
| studies on karyotypes of south african argasidae. i. ornithodoros savignyi. (audouin) (1827). | | 1966 | 5967511 |
| the use of red cell antigens for timing break-down of erythrocytes during digestion in ornithodoros savignyi (audouin, 1827). | | 1966 | 5971581 |
| laboratory vector studies on six mosquito and one tick species with chikungunya virus. | the tick ornithodoros savignyi and the mosquitoes culex horridus, culex quinquefasciatus, aedes fulgens, ae. furcifer and mansonia africana were tested for infection rates and ability to transmit chikungunya virus. o. savignyi and cx quinquefasciatus did not become infected and cx quinquefasciatus failed to transmit the virus between vervet monkeys, cercopithecus aethiops. only one of 17 cx horridus feeding on a blood-virus mixture became infected which included infection of the salivary glands. ... | 1981 | 6115488 |
| efficacy of ivermectin against the sand tampan (ornithodoros savignyi). | | 1984 | 6546824 |
| borrelia crocidurae localization and transmission in ornithodoros erraticus and o. savignyi. | borrelia crocidurae infection rates in different organs of adult ornithodoros (pavlovskyella) erraticus and o. (ornithodoros) savignyi were studied at intervals during a 60-day period following an infective meal. the spirochaetes persisted in tick guts for 1 month, were first observed in other organs 1-7 days post-feeding, and persisted for 20-60 days in different organs. the ovaries, gene's organ, testes and male accessory glands of only o. erraticus were infected. the infection rates in adult ... | 1984 | 6739127 |
| biochemical changes in the coxal organ proper and accessory glands of female ornithodoros (ornithodoros) savignyi at different physiological conditions. | changes in the total protein, dna, rna, lipid and phospholipid concentrations in the coxal organ proper and accessory glands of ornithodoros (ornithodoros) savignyi (audouin) were studied. there was an increase in the total protein, dna, rna, lipid and phospholipid content of the coxal organ proper in the female upto 6-days after feeding, then the concentration decreased. also, the content of protein, dna, rna, lipid and phospholipid in the coxal organ proper of the seventh nymphal instar were s ... | 1994 | 7513331 |
| identification of anticoagulant activities in the salivary glands of the soft tick, ornithodoros savignyi. | salivary gland extracts of the sand tampan, ornithodoros savignyi, prolonged the activated partial thromboplastin time (aptt) and prothrombin time (pt) significantly in a concentration-dependent manner. there was also a pronounced inhibition of human activated factor xa (fxa) by salivary gland extracts. the salivary gland extracts inhibited chromogenic assays specific for both fxa and thrombin. sodium dodecyl sulphate-polyacrylamide gel electrophoresis (sds-page) of the salivary gland proteins f ... | 1995 | 7656730 |
| isolation and characterization of an anticoagulant from the salivary glands of the tick, ornithodoros savignyi (acari: argasidae). | an inhibitor of activated coagulation factor x (fxa) was isolated from salivary gland extracts prepared from ornithodoros savignyi using a two-step procedure, involving reversed-phase high-performance liquid chromatography (rp-hplc) and diethylaminoethyl (deae) ion-exchange chromatography. from its behaviour during deae chromatography it could be deduced that it possesses an acidic pi (approximately 4.6). capillary zone electrophoresis (cze) of the purified inhibitor showed it to be homogeneous. ... | 1996 | 8952072 |
| african swine fever virus infection in the argasid host, ornithodoros porcinus porcinus. | the pathogenesis of african swine fever virus (asfv) infection in ornithodoros porcinus porcinus was examined in nymphal ticks infected with the asfv isolate chiredzi/83/1. at times postinfection (p.i.) ranging from 6 h to 290 days, ticks or dissected tick tissues were titrated for virus and examined ultrastructurally for evidence of virus replication. the asfv infection rate in ticks was 100% in these experiments, and virus infection was not associated with a significant increase in tick mortal ... | 1998 | 9499019 |
| apyrase activity and platelet aggregation inhibitors in the tick ornithodoros savignyi (acari: argasidae). | ticks are ectoparasites that cause considerable damage to their hosts while feeding. the feeding process is facilitated by anti-haemostatic factors present in the tick saliva. apyrase (atp diphosphohydrolase, ec 3.6.1.5) is a platelet aggregation inhibitor found in most haematophagous organisms studied. the present study describes the identification and characterization of such an activity in the tick ornithodoros savignyi. the enzyme conformed to many properties common to apyrases. these includ ... | 1998 | 9652096 |
| cloning, nucleotide sequence and expression of the gene encoding factor xa inhibitor from the salivary glands of the tick, ornithodoros savignyi. | the n-terminal sequence of the competitive and slow tight-binding factor xa inhibitor (fxai; ki = 0.83 +/- 0.10 nm) isolated from the salivary glands of ornithodoros savignyi ticks (acari: argasidae) was employed to design a degenerate gene-specific primer (gsp) for 3'-rapid amplification of cdna ends (3'-race). the primer consisted of a sequence encoding for amino acid residues 5-11. a full-length gene was next constructed from the 3'-race product in a two-step pcr procedure and successfully ex ... | 1998 | 9890144 |
| [peptides as inhibitors of thrombin coagulation activity and of thrombocyte aggregation]. | the analysis of literature and our own data of regulatory peptides influence on the blood coagulation system is presenting. various natural and synthetic peptides inhibit the activity of thrombin and platelet aggregation. direct specific inhibitors of thrombin are peptides developed on the base of d-phe-pro-arg sequence. strong specific inhibitors of the prothrombinase complex factor xa were isolated from tissues and saliva of the blood-sucking organisms. these inhibitors decrease thrombin gener ... | 1999 | 10420478 |
| african swine fever virus replication in the midgut epithelium is required for infection of ornithodoros ticks. | although the malawi lil20/1 (mal) strain of african swine fever virus (asfv) was isolated from ornithodoros sp. ticks, our attempts to experimentally infect ticks by feeding them this strain failed. ten different collections of ornithodorus porcinus porcinus ticks and one collection of o. porcinus domesticus ticks were orally exposed to a high titer of mal. at 3 weeks postinoculation (p.i.), <25% of the ticks contained detectable virus, with viral titers of <4 log(10) 50% hemadsorbing doses/ml. ... | 1999 | 10482612 |
| savignin, a potent thrombin inhibitor isolated from the salivary glands of the tick ornithodoros savignyi (acari: argasidae). | a thrombin (e.c. 3.4.21.5) inhibitor, savignin, was isolated from the salivary glands of ornithodoros savignyi by a combination of size exclusion, anion-exchange, and reversed-phase chromatography. the inhibitor has a molecular mass of 12,430.4 da as determined by electrospray mass spectrometry. the behavior of savignin during anion-exchange chromatography indicated that it has an acidic pi. the available n-terminal sequence (residues 1-11) differed from that of ornithodorin with only one residu ... | 1999 | 10502470 |
| disaggregation of aggregated platelets by apyrase from the tick, ornithodoros savignyi (acari: argasidae). | apyrase, secreted by ticks during feeding, is a platelet aggregation inhibitor that functions as a regulator of the host's hemostatic system. this present study concerns the disaggregation effect of salivary gland apyrase from the tick ornithodoros savignyi. secondarily aggregated platelets, disaggregated by apyrase, exhibited a reversal of shape from a spherical (aggregated) form to a discoid form, reminiscent of reversible aggregation at low adp concentrations in citrated platelet-rich plasma. ... | 2000 | 11110238 |
| first record of natural infection with borrelia in ornithodoros (ornithodoros) savignyi. reservoir potential and specificity of the tick to borrelia. | field and laboratory data provided convincing evidence implicating o. savignyi at shelateen, halayeb province as a reservoir and a vector of a specific borrelia. using direct immunofluorescence borrelia infection was detected for the first time in a natural population of o. savignyi in egypt. the overall infection rate (ir) was relatively high (50.63%) and the infected ticks were capable of transmitting the infection to hamsters during feeding. infected nymphs maintained borrelial infection tran ... | 2000 | 11198375 |
| savignygrin, a platelet aggregation inhibitor from the soft tick ornithodoros savignyi, presents the rgd integrin recognition motif on the kunitz-bpti fold. | savignygrin, a platelet aggregation inhibitor that possesses the rgd integrin recognition motif, has been purified from the soft tick ornithodoros savignyi. two isoforms with similar biological activities differ because of r52g and n60g in their amino acid sequences, indicating a recent gene duplication event. platelet aggregation induced by adp (ic50, 130 nm), collagen, the thrombin receptor-activating peptide, and epinephrine was inhibited, although platelets were activated and underwent a sha ... | 2002 | 11932256 |
| amino acid sequence and structure modeling of savignin, a thrombin inhibitor from the tick, ornithodoros savignyi. | the full-length gene of savignin, a potent thrombin (e.c. 3.4.21.5) inhibitor from the tick ornithodoros savignyi has been cloned and sequenced. both 5' and 3' utr's, a signal peptide from the translated amino acid sequence and an unusual poly-adenylation signal (aataca) has been identified. the translated protein sequence shows high identity (63%) with ornithodorin, the thrombin inhibitor from the tick, ornithodoros moubata. molecular modeling using the structure of ornithodorin as reference ga ... | 2002 | 12044499 |
| pathogenic mechanisms of sand tampan toxicoses induced by the tick, ornithodoros savignyi. | the tick, ornithodoros savignyi has been implicated in inducing paralysis and tampan toxicosis. in this study, a basic toxin (tsgp4) was identified and the presence of an acidic toxin (tsgp2) was confirmed. both basic and acidic toxins were more lethal than previously described, with tsgp4 (34microg) and tsgp2 (24microg) causing mortality of adult mice within 30min. pathological effects on the cardiac system, notably of salivary gland extract on an isolated rat heart perfusion system and of puri ... | 2002 | 12076655 |
| identification of extrinsic blood coagulation pathway inhibitors from the tick ornithodoros savignyi (acari: argasidae). | the salt baso(4) selectively adsorbs two proteins from crude ornithodoros savignyi salivary gland extract. they co-purify during reversed-phase hplc, but can be separated by hydrophobic-interaction chromatography. their molecular masses are 9333 and 9173da. the 9.3kda protein was designated bsap1 and the 9.1kda protein bsap2. their amino acid compositions show significant differences, in particular the presence of seven and eight cysteine residues in bsap1 and bsap2, respectively. the proteins d ... | 2002 | 12427468 |
| disaggregation of aggregated platelets by savignygrin, a alphaiibeta3 antagonist from ornithodoros savignyi. | ticks control their host's hemostatic system by secretion of bioactive components during feeding that inhibit blood coagulation and platelet aggregation. dissolution of platelets that have already aggregated can enhance control over the hemostatic system. it has been shown that disaggregation of aggregated platelets by the enzyme apyrase was accompanied by a shape change from the aggregated spherical form back to the discoid form associated with un-activated platelets. the present study concerns ... | 2002 | 12593588 |
| the influence of tick behavior, biotope and host specificity on concerted evolution of the platelet aggregation inhibitor savignygrin, from the soft tick ornithodoros savignyi. | ticks are obligate blood-feeding parasites that secrete anti-hemostatic components during feeding to enable control of the hemostatic system of the host. complex interactions at the tick-host interface are an indication of the important role that the host played during tick evolution. the question is to what extent interaction with the host and the environment influences tick evolution. previously, two isoforms (97% sequence identity) of savignygrin, an alphaiibbeta3 antagonist, have been descri ... | 2003 | 12770580 |
| the major tick salivary gland proteins and toxins from the soft tick, ornithodoros savignyi, are part of the tick lipocalin family: implications for the origins of tick toxicoses. | the origins of tick toxicoses remain a subject of controversy because no molecular data are yet available to study the evolution of tick-derived toxins. in this study we describe the molecular structure of toxins from the soft tick, ornithodoros savignyi. the tick salivary gland proteins (tsgps) are four highly abundant proteins proposed to play a role in salivary gland granule biogenesis of the soft tick o. savignyi, of which the toxins tsgp2 and tsgp4 are a part. they were assigned to the lipo ... | 2003 | 12777525 |
| the identity of ornithodoros savignyi (audouin, 1827) and o. pavimentosus neumann, 1901 (ixodoidea, argasidae). | | 1955 | 13252492 |
| is ornithodoros savignyi (audouin) a vector of relapsing fever in africa? | | 1960 | 14400772 |
| purification and characterization of apyrase from the tick, ornithodoros savignyi. | | 1998 | 14598857 |
| ornithodoros savignyi (audouin) 1826, argasidae, in the embu district of kenya colony. | | 1951 | 14840375 |
| the mechanism of alphaiibbeta3 antagonism by savignygrin and its implications for the evolution of anti-hemostatic strategies in soft ticks. | savignygrin, a alphaiibbeta3 antagonist presents the rgd sequence on the substrate-binding loop of the (bpti-fold). this study investigated whether this is the only integrin-targeting motif associated with its mechanism. it forms a tight-binding complex with alphaiibbeta3 that is resistant to sds dissociation under reducing and non-reducing conditions, but not to temperature or edta. the same complex is formed on resting and activated platelets, as well as aggregated platelets that have been dis ... | 2004 | 15147758 |
| exon-intron structure of outlier tick lipocalins indicate a monophyletic origin within the larger lipocalin family. | all tick proteins assigned to the lipocalin family lack the structural conserved regions (scrs) that are characteristic of the kernel lipocalins and can thus be classified as outliers. these tick proteins have been assigned to the tick lipocalin family based on database searches that indicated homology between tick sequences and the fact that the histamine binding protein (hbp2) from the hard tick rhipicephalus appendiculatus (ixodidae) shows structural similarity to the lipocalin fold. sequence ... | 2004 | 15147759 |
| a reassessment of argasid tick salivary gland ultrastructure from an immuno-cytochemical perspective. | previous morphological and histochemical studies of argasid tick salivary glands indicated that they were less complex than ixodid salivary glands, with only three granular cell types. the present study shows that there exist at least four different granular cell types in the salivary glands of the argasid tick ornithodoros savignyi, based on immuno-localization of the anti-hemostatic factors, apyrase and savignygrin. both anti-hemostatic factors were localized to dense core granule type 'a' and ... | 2004 | 15285144 |
| molecular crowding as a mechanism for tick secretory granule biogenesis. | during feeding ticks secrete bioactive components into the host to counter-act its immune and hemostatic defense systems. these bioactive components are stored in secretory granules that are secreted during feeding in an exocrine stimulus-response type of mechanism. all proteins destined for secretion are packaged into these granules during granule biogenesis. up to date no mechanism for granule biogenesis has been proposed, except to note that biogenesis occurs under conditions of high protein ... | 2004 | 15522614 |
| epidemiology and transmission dynamics of west nile virus disease. | from 1937 until 1999, west nile virus (wnv) garnered scant medical attention as the cause of febrile illness and sporadic encephalitis in parts of africa, asia, and europe. after the surprising detection of wnv in new york city in 1999, the virus has spread dramatically westward across the united states, southward into central america and the caribbean, and northward into canada, resulting in the largest epidemics of neuroinvasive wnv disease ever reported. from 1999 to 2004, >7,000 neuroinvasiv ... | 2005 | 16102302 |
| the transcriptome of the salivary glands of the female western black-legged tick ixodes pacificus (acari: ixodidae). | sequencing of an ixodes pacificus salivary gland cdna library yielded 1068 sequences with an average undetermined nucleotide of 1.9% and an average length of 487 base pairs. assembly of the expressed sequence tags yielded 557 contigs, 138 of which appear to code for secreted peptides or proteins based on translation of a putative signal peptide. based on the blastx similarity of these contigs to 66 matches of ixodes scapularis peptide sequences, only 58% sequence identity was found, indicating a ... | 2005 | 16102420 |
| alkhurma hemorrhagic fever virus in ornithodoros savignyi ticks. | evidence for the tickborne nature of alkhurma hemorrhagic fever virus (ahfv) is indirect because ahfv has not been detected in arthropods. one ornithodoros savignyi tick from saudi arabia contained ahfv rna. this is the first direct evidence that ahfv is a tickborne flavivirus and confirms the association between human ahfv cases and tickbite history. | 2007 | 17370534 |
| the structure of omci, a novel lipocalin inhibitor of the complement system. | the complement (c) system is a potent innate immune defence system against parasites. we have recently characterised and expressed omci, a 16 kda protein derived from the soft tick ornithodoros moubata that specifically binds c5, thereby preventing c activation. the structure of recombinant omci determined at 1.9 a resolution confirms a lipocalin fold and reveals that the protein binds a fatty acid derivative that we have identified by mass spectrometry as ricinoleic acid. we propose that omci c ... | 2007 | 17445829 |
| an insight into the sialome of the soft tick, ornithodorus parkeri. | while hard ticks (ixodidae) take several days to feed on their hosts, soft ticks (argasidae) feed faster, usually taking less than 1h per meal. saliva assists in the feeding process by providing a cocktail of anti-hemostatic, anti-inflammatory and immunomodullatory compounds. saliva of hard ticks has been shown to contain several families of genes each having multiple members, while those of soft ticks are relatively unexplored. analysis of the salivary transcriptome of the soft tick ornithodoru ... | 2008 | 18070662 |
| characterization of anti-hemostatic factors in the argasid, argas monolakensis: implications for the evolution of blood-feeding in the soft tick family. | to date, the only anti-hemostatic factors characterized for softs ticks are for ornithodoros moubata and ornithodoros savignyi, ticks that feeds mainly on mammals. this includes thrombin (ornithodorin and savignin), fxa (tap and fxai) and platelet aggregation (disagegin and savignygrin) inhibitors that belong to the bpti-kunitz protein family. this raises the question on how well anti-hemostatic factors will be conserved in other soft tick genera that feeds on other vertebrates such as birds. we ... | 2008 | 18070663 |
| comparative sialomics between hard and soft ticks: implications for the evolution of blood-feeding behavior. | ticks evolved various mechanisms to modulate their host's hemostatic and immune defenses. differences in the anti-hemostatic repertoires suggest that hard and soft ticks evolved anti-hemostatic mechanisms independently, but raise questions on the conservation of salivary gland proteins in the ancestral tick lineage. to address this issue, the sialome (salivary gland secretory proteome) from the soft tick, argas monolakensis, was determined by proteomic analysis and cdna library construction of s ... | 2008 | 18070664 |
| distantly related lipocalins share two conserved clusters of hydrophobic residues: use in homology modeling. | lipocalins are widely distributed in nature and are found in bacteria, plants, arthropoda and vertebra. in hematophagous arthropods, they are implicated in the successful accomplishment of the blood meal, interfering with platelet aggregation, blood coagulation and inflammation and in the transmission of disease parasites such as trypanosoma cruzi and borrelia burgdorferi. the pairwise sequence identity is low among this family, often below 30%, despite a well conserved tertiary structure. under ... | 2008 | 18190694 |
| isolation, cloning and structural characterisation of boophilin, a multifunctional kunitz-type proteinase inhibitor from the cattle tick. | inhibitors of coagulation factors from blood-feeding animals display a wide variety of structural motifs and inhibition mechanisms. we have isolated a novel inhibitor from the cattle tick boophilus microplus, one of the most widespread parasites of farm animals. the inhibitor, which we have termed boophilin, has been cloned and overexpressed in escherichia coli. mature boophilin is composed of two canonical kunitz-type domains, and inhibits not only the major procoagulant enzyme, thrombin, but i ... | 2008 | 18286181 |
| structure, function, and evolution of biogenic amine-binding proteins in soft ticks. | two highly abundant lipocalins, monomine and monotonin, have been isolated from the salivary gland of the soft tick argas monolakensis and shown to bind histamine and 5-hydroxytryptamine (5-ht), respectively. the crystal structures of monomine and a paralog of monotonin were determined in the presence of ligands to compare the determinants of ligand binding. both the structures and binding measurements indicate that the proteins have a single binding site rather than the two sites previously des ... | 2008 | 18445596 |
| insight into the sialome of the castor bean tick, ixodes ricinus. | in recent years, there have been several sialome projects revealing transcripts expressed in the salivary glands of ticks, which are important vectors of several human diseases. here, we focused on the sialome of the european vector of lyme disease, ixodes ricinus. | 2008 | 18489795 |
| a novel clade of cysteinyl leukotriene scavengers in soft ticks. | inflammation is an important vertebrate defense mechanism against ecto-parasites for which ticks have evolved numerous mechanisms of modulation. am-33 and tsgp4, related lipocalins from the soft ticks argas monolakensis and ornithodoros savignyi bind cysteinyl leukotrienes with high affinity as measured by isothermal titration calorimetry. this was confirmed in a smooth muscle bioassay that measured contraction of guinea pig ileum induced by leukotriene c4 where both proteins inhibited contracti ... | 2008 | 18675910 |
| function, mechanism and evolution of the moubatin-clade of soft tick lipocalins. | the "moubatin-clade" of soft tick lipocalins, although monophyletic, shows clear signs of paralogy as indicated by the various functions associated with this protein family. this includes anti-platelet (moubatin), anti-complement (omci) and toxic (tsgp2) activities in the vertebrate host. in order to understand the evolution of function and how it relates to the various paralogs in this clade, we characterized a number of different proteins in regard to undefined function and mechanism. by utili ... | 2008 | 18694828 |
| an insight into the salivary transcriptome and proteome of the soft tick and vector of epizootic bovine abortion, ornithodoros coriaceus. | the salivary glands of blood-sucking arthropods contain a redundant 'magic potion' that counteracts their vertebrate host's hemostasis, inflammation, and immunity. we here describe the salivary transcriptome and proteomics (sialome) of the soft tick ornithodoros coriaceus. the resulting analysis helps to consolidate the classification of common proteins found in both soft and hard ticks, such as the lipocalins, kunitz, cystatin, basic tail, hebraein, defensin, til domain, metalloprotease, 5'-nuc ... | 2008 | 18725333 |
| exploring the mialome of ticks: an annotated catalogue of midgut transcripts from the hard tick, dermacentor variabilis (acari: ixodidae). | ticks are obligate blood feeders. the midgut is the first major region of the body where blood and microbes ingested with the blood meal come in contact with the tick's internal tissues. little is known about protein expression in the digestive tract of ticks. in this study, for analysis of global gene expression during tick attachment and feeding, we generated and sequenced 1,679 random transcripts (ests) from cdna libraries from the midguts of female ticks at varying stages of feeding. | 2008 | 19021911 |
| ixodes ricinus tick lipocalins: identification, cloning, phylogenetic analysis and biochemical characterization. | during their blood meal, ticks secrete a wide variety of proteins that interfere with their host's defense mechanisms. among these proteins, lipocalins play a major role in the modulation of the inflammatory response. | 2008 | 19096708 |
| ornithodoros savignyi: soft tick apyrase belongs to the 5'-nucleotidase family. | salivary apyrases are nucleotide-metabolising enzymes that blood-feeding parasites utilise for modulation of extracellular nucleotides to prevent platelet activation and aggregation. in this study a 5'-nucleotidase specific degenerate primer was used to identify homologous transcripts from ornithodoros savignyi salivary gland cdna. two 5'-nucleotidase isoforms that share significant sequence identity to putative apyrases from rhipicephalus appendiculatus and ixodes scapularis were identified. st ... | 2009 | 19393241 |
| ixodes scapularis tick serine proteinase inhibitor (serpin) gene family; annotation and transcriptional analysis. | serine proteinase inhibitors (serpins) are a large superfamily of structurally related, but functionally diverse proteins that control essential proteolytic pathways in most branches of life. given their importance in the biology of many organisms, the concept that ticks might utilize serpins to evade host defenses and immunizing against or disrupting their functions as targets for tick control is an appealing option. | 2009 | 19435496 |
| functional characterization of a salivary apyrase from the sand fly, phlebotomus duboscqi, a vector of leishmania major. | two transcripts coding for proteins homologous to apyrases were identified by massive sequencing of a phlebotomus (p.) duboscqi salivary gland cdna library. the sequence analysis revealed that the amino acids important for enzymatic activity including nucleotidase activity and the binding of calcium and nucleotides were well conserved in these molecules. a recombinant p. duboscqi salivary apyrase was expressed in escherichia coli and purified. the resulting protein efficiently hydrolyzed adp and ... | 2009 | 19651132 |
| rhipicephalus (boophilus) microplus: clotting time in tick-infested skin varies according to local inflammation and gene expression patterns in tick salivary glands. | ticks deposit saliva at the site of their attachment to a host in order to inhibit haemostasis, inflammation and innate and adaptive immune responses. the anti-haemostatic properties of tick saliva have been described by many studies, but few show that tick infestations or its anti-haemostatic components exert systemic effects in vivo. in the present study, we extended these observations and show that, compared with normal skin, bovine hosts that are genetically susceptible to tick infestations ... | 2010 | 20045690 |
| a proteomics approach for the analysis of hemolymph proteins involved in the immediate defense response of the soft tick, ornithodoros savignyi, when challenged with candida albicans. | a proteomics approach was employed to identify proteins secreted into the hemolymph of ornithodorus savignyi ticks 2 h after immune-challenge with the yeast, candida albicans. profiling of the proteins present in hemolymph of unchallenged ticks versus ticks challenged with heat-killed yeast revealed five proteins to be differentially expressed. the modulated protein spots were subjected to tandem mass spectrometry (ms/ms) analysis, but could not be positively identified. these proteins can be as ... | 2010 | 20186467 |
| potential role of ticks as vectors of bluetongue virus. | when the first outbreak of bluetongue virus serotype 8 (btv8) was recorded in north-west europe in august 2006 and renewed outbreaks occurred in the summer of 2007 and again in 2008, the question was raised how the virus survived the winter. since most adult culicoides vector midges are assumed not to survive the northern european winter, and transovarial transmission in culicoides is not recorded, we examined the potential vector role of ixodid and argasid ticks for bluetongue virus. four speci ... | 2010 | 20358393 |
| savicalin, a lipocalin from hemocytes of the soft tick, ornithodoros savignyi. | savicalin, is a lipocalin found in the hemocytes of the soft tick, ornithodoros savignyi. it could be assigned to the tick lipocalin family based on blast analysis. savicalin is the first non-salivary gland lipocalin described in ticks. the mature sequence is composed of 188 amino acids with a molecular mass of 21481.9 da. a homolog for savicalin was found in a whole body est-library from a related soft tick o. porcinus, while other tick salivary gland derived lipocalins retrieved from the non-r ... | 2010 | 20512614 |
| bm86 homologues and novel ataq proteins with multiple epidermal growth factor (egf)-like domains from hard and soft ticks. | tick control on livestock relies principally on the use of acaricides but the development of acaricide resistance and concerns for environmental pollution underscore the need for alternative control methods, for instance through the use of anti-tick vaccines. two commercial vaccines based on the recombinant bm86 protein from rhipicephalus (boophilus) microplus ticks were developed. partial protection of the bm86 vaccine against other rhipicephalus (boophilus) and hyalomma tick species suggests t ... | 2010 | 20647015 |
| alkhurma hemorrhagic fever in humans, najran, saudi arabia. | alkhurma virus is a flavivirus, discovered in 1994 in a person who died of hemorrhagic fever after slaughtering a sheep from the city of alkhurma, saudi arabia. since then, several cases of alkhurma hemorrhagic fever (alkhf), with fatality rates up to 25%, have been documented. from january 1, 2006, through april 1, 2009, active disease surveillance and serologic testing of household contacts identified alkhf in 28 persons in najran, saudi arabia. for epidemiologic comparison, serologic testing ... | 2010 | 21122217 |
| alkhurma hemorrhagic fever in travelers returning from egypt, 2010. | two travelers returning to italy from southern egypt were hospitalized with a fever of unknown origin. test results showed infection with alkhurma virus. the geographic distribution of this virus could be broader than previously thought. | 2010 | 21122237 |
| bloodmeal size and spirochete acquisition of ornithodoros hermsi (acari: argasidae) during feeding. | ornithodoros hermsi wheeler (acari: argasidae) is the vector of borrelia hermsii, the primary cause of tick-borne relapsing fever in north america. this tick is one of the smallest ornithodoros species involved with the biological transmission of spirochetes; yet, the amount of blood ingested while feeding is unknown. therefore, we determined the amount of blood o. hermsi ingested during a bloodmeal to establish its potential for spirochete acquisition while feeding on an infected host. ticks at ... | 2010 | 21175068 |
| cloning, characterization and diagnostic performance of the salivary lipocalin protein tsgp1 from ornithodoros moubata. | the argasid tick ornithodoros moubata is distributed throughout south and east africa and madagascar, where it colonizes wild and domestic habitats and feeds on warthogs, domestic swine, and humans. this argasid transmits the spirochete borrelia duttonii, causing east african tick-borne relapsing fever in humans, and the african swine fever virus, which causes a highly lethal haemorrhagic disease in pigs. tick surveillance and the elimination of o. moubata from synanthropic environments (human d ... | 2010 | 21216104 |
| detection of tick blood parasites in egypt using pcr assay ii- borrelia burgdorferi sensu lato. | the prevalence of borrelia burgdorferi sensu lato (s.l.), the etiologic agent of lyme borrelosis (lb), was determined for the first time in egypt by using polymerase chain reaction (pcr). questing 5243 hard and soft ticks were collected from animal farms throughout giza governorate. dna from 500 individual tick species was extracted and pcr was performed. primers verified from the sequence of german strain pko of borrelia afzelii were used. fragments of 642 bp were generated and sequenced. the p ... | 2010 | 21268526 |
| tick paralysis in australia caused by ixodes holocyclus neumann. | ticks are obligate haematophagous ectoparasites of various animals, including humans, and are abundant in temperate and tropical zones around the world. they are the most important vectors for the pathogens causing disease in livestock and second only to mosquitoes as vectors of pathogens causing human disease. ticks are formidable arachnids, capable of not only transmitting the pathogens involved in some infectious diseases but also of inducing allergies and causing toxicoses and paralysis, wit ... | 2011 | 21396246 |
| kyasanur forest disease virus alkhurma subtype in ticks, najran province, saudi arabia. | to the editor: the lineage of kyasanur forest disease virus (kfdv) found in the kingdom of saudi arabia is commonly referred to as alkhurma hemorrhagic fever virus (ahfv). this virus was first isolated from a specimen collected in 1994 from a butcher living in makkah province, who was hospitalized for a hemorrhagic fever from which he died (1). the virus was assigned to the genus flavivirus on the basis of reactivity with genus-specific monoclonal antibodies and sequencing of a fragment of the n ... | 2011 | 21529425 |
| Seroprevalence of alkhurma and other hemorrhagic Fever viruses, saudi arabia. | A 2009 deployment of military units from several Saudi Arabian provinces to Jazan Province, Saudi Arabia, enabled us to evaluate exposure to Alkhurma, Crimean-Congo, dengue, and Rift Valley hemorrhagic fever viruses. Seroprevalence to all viruses was low; however, Alkhurma virus seroprevalence was higher (1.3%) and less geographically restricted than previously thought. | 2011 | 22172587 |
| ancient ancestry of kfdv and ahfv revealed by complete genome analyses of viruses isolated from ticks and mammalian hosts. | alkhurma hemorrhagic fever virus (ahfv) and kyasanur forest disease virus (kfdv) cause significant human disease and mortality in saudi arabia and india, respectively. despite their distinct geographic ranges, ahfv and kfdv share a remarkably high sequence identity. given its emergence decades after kfdv, ahfv has since been considered a variant of kfdv and thought to have arisen from an introduction of kfdv to saudi arabia from india. to gain a better understanding of the evolutionary history o ... | 2011 | 21991403 |
| tick cell lines for study of crimean-congo hemorrhagic fever virus and other arboviruses. | abstract continuous cell lines derived from many of the vectors of tick-borne arboviruses of medical and veterinary importance are now available. their role as tools in arbovirus research to date is reviewed and their potential application in studies of tick cell responses to virus infection is explored, by comparison with recent progress in understanding mosquito immunity to arbovirus infection. a preliminary study of propagation of the human pathogen crimean-congo hemorrhagic fever virus (cc ... | 2011 | 21955214 |
| evolution, expansion and expression of the kunitz/bpti gene family associated with long-term blood feeding in ixodes scapularis. | abstract: background: recent studies of the tick saliva transcriptome have revealed the profound role of salivary proteins in blood feeding. kunitz/bpti proteins are abundant in the salivary glands of ticks and perform multiple functions in blood feeding, such as inhibiting blood coagulation, regulating host blood supply and disrupting host angiogenesis. however, kunitz/bpti proteins in soft and hard ticks have different functions and molecular mechanisms. how these differences emerged and whet ... | 2012 | 22244187 |
| salivating for knowledge: potential pharmacological agents in tick saliva. | | 2008 | 18271624 |
| tick salivary secretion as a source of antihemostatics. | ticks are mostly obligatory blood feeding ectoparasites that have an impact on human and animal health. in addition to direct damage due to feeding, some tick species serve as the vectors for the causative agents of several diseases, such as the spirochetes of the genus borrelia causing lyme disease, the virus of tick-borne encephalitis, various rickettsial pathogens or even protozoan parasites like babesia spp. hard ticks are unique among bloodfeeders because of their prolonged feeding period t ... | 2012 | 22564820 |
| tick salivary compounds: their role in modulation of host defences and pathogen transmission. | ticks require blood meal to complete development and reproduction. multifunctional tick salivary glands play a pivotal role in tick feeding and transmission of pathogens. tick salivary molecules injected into the host modulate host defence responses to the benefit of the feeding ticks. to colonize tick organs, tick-borne microorganisms must overcome several barriers, i.e., tick gut membrane, tick immunity, and moulting. tick-borne pathogens co-evolved with their vectors and hosts and developed m ... | 2013 | 23971008 |
| borrelia hermsii acquisition order in superinfected ticks determines transmission efficiency. | multilocus sequence typing of borrelia hermsii isolates reveals its divergence into two major genomic groups (gg), but no differences in transmission efficiency or host pathogenicity are associated with these genotypes. to compare ggi and ggii in the tick-host infection cycle, we first determined if spirochetes from the two groups could superinfect the tick vector ornithodoros hermsi. we infected mice with isolates from each group and fed ticks sequentially on these mice. we then fed the infecte ... | 2013 | 23716615 |
| cellular function and molecular structure of ecto-nucleotidases. | ecto-nucleotidases play a pivotal role in purinergic signal transmission. they hydrolyze extracellular nucleotides and thus can control their availability at purinergic p2 receptors. they generate extracellular nucleosides for cellular reuptake and salvage via nucleoside transporters of the plasma membrane. the extracellular adenosine formed acts as an agonist of purinergic p1 receptors. they also can produce and hydrolyze extracellular inorganic pyrophosphate that is of major relevance in the c ... | 2012 | 22555564 |
| chikungunya virus-vector interactions. | chikungunya virus (chikv) is a mosquito-borne alphavirus that causes chikungunya fever, a severe, debilitating disease that often produces chronic arthralgia. since 2004, chikv has emerged in africa, indian ocean islands, asia, europe, and the americas, causing millions of human infections. central to understanding chikv emergence is knowledge of the natural ecology of transmission and vector infection dynamics. this review presents current understanding of chikv infection dynamics in mosquito v ... | 2014 | 25421891 |
| the salivary secretome of the biting midge, culicoides sonorensis. | culicoides biting midges (diptera: ceratopogonidae) are hematophagous insects with over 1400 species distributed throughout the world. many of these species are of particular agricultural importance as primary vectors of bluetongue and schmallenberg viruses, yet little is known about culicoides genomics and proteomics. detailed studies of members from other blood-feeding dipteran families, including those of mosquito (culicidae) and black fly (simuliidae), have shown that protein components with ... | 2014 | 24949243 |
| alkhurma viral hemorrhagic fever virus: proposed guidelines for detection, prevention, and control in saudi arabia. | | 2012 | 22860139 |
| kyasanur forest disease. | in the spring of 1957, an outbreak of severe disease was documented in people living near the kyasanur forest in karnataka state, india, which also affected wild nonhuman primates. collection of samples from dead animals and the use of classical virological techniques led to the isolation of a previously unrecognized virus, named kyasanur forest disease virus (kfdv), which was found to be related to the russian spring-summer encephalitis (rsse) complex of tick-borne viruses. further evaluation f ... | 2012 | 23110991 |
| kyasanur forest disease virus infection in mice is associated with higher morbidity and mortality than infection with the closely related alkhurma hemorrhagic fever virus. | kyasanur forest disease virus (kfdv) and alkhurma hemorrhagic fever virus (ahfv) are closely related members of the flavivirus genus and are important causes of human disease in india and the arabian peninsula, respectively. despite high genetic similarity, the viruses have distinctly different host ranges and ecologies. human cases of kfdv or ahfv develop a spectrum of disease syndromes ranging from liver pathology to neurologic disease. case reports suggest kfdv is more commonly associated wit ... | 2014 | 24950196 |
| a sero-epidemiological study of arboviral fevers in djibouti, horn of africa. | arboviral infections have repeatedly been reported in the republic of djibouti, consistent with the fact that essential vectors for arboviral diseases are endemic in the region. however, there is a limited recent information regarding arbovirus circulation, and the associated risk predictors to human exposure are largely unknown. we performed, from november 2010 to february 2011 in the djibouti city general population, a cross-sectional elisa and sero-neutralisation-based sero-epidemiological an ... | 2014 | 25502692 |
| analysis of the langat virus genome in persistent infection of an ixodes scapularis cell line. | tick-borne flaviviruses (tbfvs) cause a broad spectrum of disease manifestations ranging from asymptomatic to mild febrile illness and life threatening encephalitis. these single-stranded positive-sense (ss(+)) rna viruses are naturally maintained in a persistent infection of ixodid ticks and small-medium sized mammals. the development of cell lines from the ixodid ticks has provided a valuable surrogate system for studying the biology of tbfvs in vitro. when we infected ise6 cells, an ixodes sc ... | 2016 | 27626437 |
| comparative pathogenesis of alkhumra hemorrhagic fever and kyasanur forest disease viruses in a mouse model. | kyasanur forest disease virus (kfdv) and alkhumra hemorrhagic fever virus (ahfv) are genetically closely-related, tick-borne flaviviruses that cause severe, often fatal disease in humans. flaviviruses in the tick-borne encephalitis (tbe) complex typically cause neurological disease in humans whereas patients infected with kfdv and ahfv predominately present with hemorrhagic fever. a small animal model for kfdv and ahfv to study the pathogenesis and evaluate countermeasures has been lacking mostl ... | 2014 | 24922308 |
| an insight into the sialome of blood-feeding nematocera. | within the diptera and outside the suborder brachycera, the blood-feeding habit occurred at least twice, producing the present day sand flies, and the culicomorpha, including the mosquitoes (culicidae), black flies (simulidae), biting midges (ceratopogonidae) and frog feeding flies (corethrellidae). alternatives to this scenario are also discussed. successful blood-feeding requires adaptations to antagonize the vertebrate's mechanisms of blood clotting, platelet aggregation, vasoconstriction, pa ... | 2010 | 20728537 |
| the salivary gland transcriptome of the neotropical malaria vector anopheles darlingi reveals accelerated evolution of genes relevant to hematophagy. | mosquito saliva, consisting of a mixture of dozens of proteins affecting vertebrate hemostasis and having sugar digestive and antimicrobial properties, helps both blood and sugar meal feeding. culicine and anopheline mosquitoes diverged ~150 mya, and within the anophelines, the new world species diverged from those of the old world ~95 mya. while the sialotranscriptome (from the greek sialo, saliva) of several species of the cellia subgenus of anopheles has been described thoroughly, no detailed ... | 2009 | 19178717 |
| platelet aggregation inhibitors from hematophagous animals. | salivary glands from blood-sucking animals (e.g., mosquitoes, bugs, sand flies, fleas, ticks, leeches, hookworms, bats) are a rich source of bioactive molecules that counteract hemostasis in a redundant and synergistic manner. this review discusses recent progress in the identification of salivary inhibitors of platelet aggregation, their molecular characterization, and detailed mechanism of action. diversity of inhibitors is remarkable, with distinct families of proteins characterized as apyras ... | 2009 | 20035779 |
| understanding the evolutionary structural variability and target specificity of tick salivary kunitz peptides using next generation transcriptome data. | ticks are blood-sucking arthropods and a primary function of tick salivary proteins is to counteract the host's immune response. tick salivary kunitz-domain proteins perform multiple functions within the feeding lesion and have been classified as venoms; thereby, constituting them as one of the important elements in the arms race with the host. the two main mechanisms advocated to explain the functional heterogeneity of tick salivary kunitz-domain proteins are gene sharing and gene duplication. ... | 2014 | 24397261 |
| the calcium activated nucleotidases: a diverse family of soluble and membrane associated nucleotide hydrolyzing enzymes. | it has long been known that the salivary glands of hematophagous (blood-feeding) arthropods secrete soluble apyrases, which are potent nucleotide hydrolyzing enzymes capable of hydrolyzing extracellular atp and adp, the latter being a major agonist contributing to platelet aggregation. only recently, however, has the identification of proteins homologous to these apyrases been reported in non-blood-feeding organisms such as rodents and humans. in this review, we present an overview of the divers ... | 2006 | 18404472 |
| salivary apyrases of triatoma infestans are assembled into homo-oligomers. | apyrase activity is present in the saliva of haematophagous arthropods. it is related to blood-feeding because of the apyrase ability to hydrolyse adp, a key component of platelet aggregation. five apyrases with apparent molecular masses of 88, 82, 79, 68 and 67 kda were identified in the saliva of the vector of chagas disease, triatoma infestans. the large size observed during purification of these enzymes suggested oligomerization. in the present study, we confirmed, using gel-filtration and a ... | 0 | 16542158 |
| disintegrins from hematophagous sources. | bloodsucking arthropods are a rich source of salivary molecules (sialogenins) which inhibit platelet aggregation, neutrophil function and angiogenesis. here we review the literature on salivary disintegrins and their targets. disintegrins were first discovered in snake venoms, and were instrumental in our understanding of integrin function and also for the development of anti-thrombotic drugs. in hematophagous animals, most disintegrins described so far have been discovered in the salivary gland ... | 2012 | 22778902 |
| arachnids of medical importance in brazil: main active compounds present in scorpion and spider venoms and tick saliva. | arachnida is the largest class among the arthropods, constituting over 60,000 described species (spiders, mites, ticks, scorpions, palpigrades, pseudoscorpions, solpugids and harvestmen). many accidents are caused by arachnids, especially spiders and scorpions, while some diseases can be transmitted by mites and ticks. these animals are widely dispersed in urban centers due to the large availability of shelter and food, increasing the incidence of accidents. several protein and non-protein compo ... | 2015 | 26273285 |
| structure and mechanism in salivary proteins from blood-feeding arthropods. | the saliva of blood-feeding arthropods contains rich mixtures of ligand binding proteins targeted at inhibiting hemostasis and inflammation in the host. since blood feeding has evolved many times, different taxonomic groups utilize completely different families of proteins to perform similar tasks. structural studies performed on a number of these proteins have revealed biologically novel and sophisticated mechanisms used to perform their functions. here, the results of these structural and mech ... | 2009 | 19925819 |
| are ticks venomous animals? | as an ecological adaptation venoms have evolved independently in several species of metazoa. as haematophagous arthropods ticks are mainly considered as ectoparasites due to directly feeding on the skin of animal hosts. ticks are of major importance since they serve as vectors for several diseases affecting humans and livestock animals. ticks are rarely considered as venomous animals despite that tick saliva contains several protein families present in venomous taxa and that many ixodida genera ... | 2014 | 25006341 |
| thrombin inhibitors from different animals. | venous and arterial thromboembolic diseases are still the most frequent causes of death and disability in high-income countries. clinical anticoagulants are inhibitors of enzymes involved in the coagulation pathway, such as thrombin and factor x(a). thrombin is a key enzyme of blood coagulation system, activating the platelets, converting the fibrinogen to the fibrin net, and amplifying its self-generation by the activation of factors v, viii, and xi. thrombin has long been a target for the deve ... | 2010 | 20976270 |
| paralog analyses reveal gene duplication events and genes under positive selection in ixodes scapularis and other ixodid ticks. | hard ticks (family ixodidae) are obligatory hematophagous ectoparasites of worldwide medical and veterinary importance. the haploid genomes of multiple species of ixodid ticks exceed 1 gbp, prompting questions regarding gene, segmental and whole genome duplication in this phyletic group. the availability of the genome assembly for the black legged tick, ixodes scapularis, and transcriptome datasets for multiple species of ticks offers an opportunity to assess the contribution of gene duplication ... | 2016 | 26984180 |