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PubMed2003

[Occurrence of Babesia microti in ticks Ixodes ricinus on selected areas of western Pomerania].

The aim of present study was to evaluate acquisition risk of babesiosis in human population exposed to ticks Ixodes ricinus by examination of Babesia microti DNA occurrence in ticks of all development stages. The polymerase chain reaction (PCR) was applied to estimate the occurrence of DNA Babesia microti in Ixodes ricinus. The Bab1 and Bab4 primers were used to amplify fragment. 238bp in length, of 18S rRNA gene for small ribosomal subunit. Amplicons were electroforeticaly separated in agarose gels. Ticks were collected in year 1999 and 2000, twice in each year in spring-summer (May-July) and summer-autumn (August-October) seasons from Goleni6w Forest and Pobierowo. These places have been classified as people attendance and tourist areas. The 716 I. ricinus ticks were collected in 1999 with 61.3% of nymphs, 17.8% larvae, 10.9% females and 9.9% males. Highest range of infection was observed in females--28.8% studied, than males--18.3%, nymphs--7.7% and larvae--3.l1%. The total number of 416 I. ricinus was collected in year 2000 with 64% of nymphs. 13.4%/males. 11.9% females and 10.7% larvae. The infection with Babesia microtri occurred only in three nymphs, which was 0.7% of studied population.

Animals↗
PubMed2006

Seasonal activity of the common European tick, Ixodes ricinus (Linnaeus, 1758), in the forested areas of the city of Olsztyn and its surroundings.

UNLABELLED: Common European ticks, Ixodes ricinus, have been found in forest areas situated within the boundaries of big cities, and in areas changed by anthropogenic pressure. Monitoring I. ricinus, in the areas used by the public for recreation and leisure, makes it possible to assess the risk of infection with the diseases they transmit. The objective of this study was the comparison of the seasonal activity of ticks, I. ricinus, in the afforested areas of the city of Olsztyn and its surroundings. MATERIAL AND METHODS: This survey was conducted at sites located in the afforested areas of Olsztyn and within the Warmiński Forest situated about 15 km from Olsztyn. Ticks, I. ricinus, were caught every 10-14 days from April to October 2001 by the commonly applied method of flagging. During each catch, the temperature (T) and relative humidity (%RH) was measured with a thermohygrometer, 1 m above the duff level. RESULTS: The tick population density at the Warmiński Forest site was higher than that at the sites within the city limits (116.8 and 20.5 ticks per 100 m2, respectively). Two peaks of tick activity were recorded in this area--the spring peak in June and the autumn peak (much lower) in September. The activity of ticks in the afforested area within the city limits was much lower--only one (spring) peak occurred, which at most sites was observed in June. At all sites, included in the study, the peak activity of ticks was observed in April. CONCLUSION: The study suggests that the afforested areas outside the city are more dangerous to people than the area within the city because of the large number of ticks there.

Animals↗
PubMed1979

[New aspects of the part of the vector played by Ixodes ricinus L. in Switzerland. Preliminary note (author's transl)].

The authors, after having recalled their recent work on Ixodes ricinus ecology, give the new results about the part played by this species in the transmission of different infectious agents in Switzerland. I. ricinus was already known to be the most important vector of the tick borne encephalitis virus, and of protozoans of the Babesia genus. In this article, we describe the existence in the hemolymphe of different I. ricinus populations, of a rickettsia species related to the RMST group (Rocky-Mountain Spotted Fever), of a trypanosome, which is close to T. theileri, and of an infectious larval form (L3) of Dipetalonema rugosicauda. An outline is suggested with the object of illustrating the functioning of a natural foci of tick encephalitis. The biological significance of the unusual presence of trypanosomes and of larval filariae in ticks is also discussed. The authors underline the fact that rickettsia, trypanosomes and filarial forms are observed for the first time in Swiss I. ricinus.

Animals↗
PubMed1986

Studies on Ricinus communis lectin--carbohydrate interaction by means of affinity electrophoresis.

The affinity gel electrophoresis of lectins purified from the seeds of Ricinus communis was studied. The mobilities of lectins on the gel showed various degree of retardation with their affinity toward their macromolecular ligand-agarose. Ricinus agglutinin which possessed the strongest affinity was retarded strongly, ricin C, and ricin B moderately, and ricin A, weakly. The concentrations of free moving ligand-galactose to reduce the retardation were also correlated very well with the potencies of affinities of lectins toward the ligand. The Kd values calculated from the retardations were 4.32 microM, 18.32 microM, 28.13 microM and 52.88 microM for ricinus agglutinin, ricin C, ricin B and ricin A respectively. Affinity gel electrophoresis was found to be a simple and quick method for studying the interaction of lectins with their ligands.

Carbohydrates↗
PubMed2003

Antifertility effects of Ricinus communis (Linn) on rats.

The antifertility effects of 50% ethanol extracts of Ricinus communis have been studied in male rats. There was a drastic reduction in the epididymal sperm counts. Alteration in the motility, mode of movement and morphology of the sperms were observed. Reductions in the fructose and testosterone levels were suggestive of reduced reproductive performance. Reversibility tests showed that the antifertility effect of Ricinus communis was completely reversible on withdrawal of the drug. The ethanol extracts of Ricinus communis did not cause any hepatotoxicity since the hepatic GOT and GPT levels were unaltered.

Acid Phosphatase↗
PubMed1997

Cloning of the cDNA for glutaredoxin, an abundant sieve-tube exudate protein from Ricinus communis L. and characterisation of the glutathione-dependent thiol-reduction system in sieve tubes.

Sieve-tube exudate protein (STEP) from Ricinus communis L. seedlings consists of a characteristic set of more than 100 different polypeptides, against which a complex antiserum was raised. This antiserum cross-reacted with dominant protein species (molecular weights 10-30 kDa) present in the sieve-tube exudate and, to a lesser extent, with proteins in tissue extracts of Ricinus and a wide range of other plant species. For further elucidation of the nature of individuals STEPs in the sieve tubes the anti-STEP serum was used to screen a cDNA expression library constructed from Ricinus cotyledon mRNA. Two clones that differed in the 3' untranslated region encoded a protein of 11 kDa which showed striking homology to bacterial and eucaryotic glutaredoxin sequences. Glutaredoxin activity was confirmed for the recombinant protein after overexpression in Escherichia coli and characterised in detail in sieve-tube exudate. Michaelis Menten constants (Km) for reduced glutathione and cysteine were 2 mM and 50 microns, respectively. Besides L-cysteine, dehydroascorbate and protein disulphides were also reduced by the activity present in the sieve-tube exudate. Glutathione, which is the obligate donor of reduced thiols for glutaredoxin, was present in sieve-tube sap in millimolar concentrations (up to 3 mM) with a ratio of total to oxidised glutathione of 3:1. It is suggested that glutaredoxin and glutathione in sieve tubes prevent oxidative damage and may be involved in redox regulation of sieve-tube proteins.

Amino Acid Sequence↗
PubMed1979

Effect of sulfhydryl reagents and protease inhibitors on sodium dodecyl sulfate-heat induced dissociation of Ricinus communis agglutinin.

Ricinus communis agglutinin dissociated to lower molecular weight forms when heated in sodium dodecyl sulfate in the absence of reducing agents, while ricin was little affected by such treatment. The data suggest that strong noncovalent bonds hold together two A-B heterodimers in the Ricinus communis agglutinin tetramer. Protease inhibitors such as diisopropylfluorophosphate, phenylmethansefulonyl fluoride, and EDTA, did not prevent the sodium dodecyl sulfate-heat induced dissociation; however, sulfhydryl specific reagents (N-ethylmaleimide, 5,5'-dithiobis (2-nitrobenzoic acid) and p-chloromercuribenzoate) were effective. Titration of the lectins in sodium dodecyl sulfate indicated that ricin contains one sulfhydryl and Ricinus communis agglutinin four sulfhydryl groups, none of which react in the presence of 8 M urea. The sulfhydryl groups that could be titrated in the intact proteins in sodium dodecyl sulfate were on the A chains.

Lectins↗
PubMed1992

Biological activity of recombinant Ricinus communis agglutinin A chain produced in Escherichia coli.

DNA encoding Ricinus communis agglutinin A chain was ligated into the E. coli expression vector pDS 5/3. Induced E. coli 71.18 cells which had been transformed with this plasmid express Ricinus communis agglutinin A chain in a soluble and biologically active form. Recombinant Ricinus communis agglutinin A chain had ribosomal RNA N-glycosidase activity and was approximately 10-fold less active than ricin A chain in a cell-free protein synthesis inhibition assay.

Cell-Free System↗
PubMed2004

The 2.0 A crystal structure and substrate specificity of the KDEL-tailed cysteine endopeptidase functioning in programmed cell death of Ricinus communis endosperm.

In the senescing endosperm of germinating castor bean (Ricinus communis) a special organelle (the ricinosome) releases a papain-type cysteine endopeptidase (CysEP) during the final stages of cellular disintegration. Protein cleavage sites for the Ricinus CysEP were determined with fluorogenic peptides (Abz-Xaa-Arg-/-Gln-Gln-Tyr(NO2)-Asp). The highest kcat/Km values were obtained with neutral amino acid residues with large aliphatic and non-polar (Leu, Val, Ile, Met) or aromatic (Phe, Tyr, Trp) side-chains. A second series (Abz-Leu-Xaa-/Gln-Pro-Tyr(NO2)-Asp) was evaluated. Based on these results, the covalent binding inhibitor H-D-Val-Leu-Lys-chloromethylketone (CMK) was chosen as substrate analogue for replacement in the catalytic site. Unusually, CysEP cleaved beta-casein N and C-terminal to the amino acid proline. CysEP was crystallized, its structure was solved by molecular replacement at 2.0 A resolution and refined to a R-factor of 18.1% (Rfree=22.6%). The polypeptide chain folds as in papain into two domains divided by the active site cleft, an elongated surface depression harboring the active site. The non-primed specificity subsites of the proteinase are clearly defined by the H-D-Val-Leu-Lys-CMK-inhibitor covalently bound to the active site. The absence of the occluding loop, which blocks the active site of exopeptidases at the C-terminal side of the scissile bond, identifies CysEP as an endopeptidase. The more open pocket of the Ricinus CysEP correlates with the extended variety of substrate amino acid residues accommodated by this enzyme, including even proline at the P1 and P1' positions. This may allow the enzyme to attack a greater variety of proteins during programmed cell death.

Amino Acid Sequence↗
PubMed1998

Expression analysis of a sucrose carrier in the germinating seedling of Ricinus communis.

This study describes the expression of a sucrose carrier at various developmental stages in Ricinus communis. A partial-length cDNA clone, RcSUT1, was isolated by RT-PCR from Ricinus seedling RNA. This is almost identical to a sucrose carrier cDNA, Rscr1, which has previously been isolated by library screening. However, we have observed a very different expression pattern in the seedling to that previously reported. Northern analysis, with RcSUT1 as a probe, revealed high expression of a 2 kb transcript in the cotyledons of the germinating seedling; transcript levels were similar in cotyledons harvested 3-6 days after germination. A much lower level of this transcript was detected in the root, hypocotyl and endosperm RNA of the seedling and very low levels were also present in the sink and source leaves of the mature plant. This pattern of expression was also reflected at the protein level with an antipeptide antibody raised to part of the RcSUT1 deduced amino acid sequence. Tissue print hybridisation analysis of the hypocotyl revealed that the sucrose carrier transcripts were localised to the phloem cells of the vascular bundles. A more detailed analysis of sucrose carrier gene expression in the cotyledons of the germinating seedling was carried out by in situ hybridisation; the strongest signals were observed from the lower epidermal layer and the phloem, consistent with an active loading role for these cells. An ultrastructural study of the cells in the lower epidermis showed that they have wall ingrowths which are characteristic of transfer cells. The results are discussed in relation to the physiological role of the sucrose carrier in the Ricinus seedling and to the pathways of sucrose movement from endosperm to the sieve elements in the cotyledons.

Amino Acid Sequence↗
PubMed1980

Fluorescence-polarization studies on binding of 4-methylumbelliferyl beta-D-galactopyranoside to Ricinus communis (castor-bean) agglutinin.

The binding of Ricinus communis (castor-bean) agglutinin 1 to saccharides was studied by equilibrium dialysis and fluorescence polarization by using the fluorescently labelled sugar 4-methylumbelliferyl beta-D-galactopyranoside. No appreciable change in ligand fluorescence of 4-methylumbelliferyl beta-D-galactopyranoside was considerably polarized on its binding to the lectin. The association constants obtained by Scatchard analysis of equilibrium-dialysis and fluorescence-polarization data do not differ much from each other, and at 25 degrees C, Ka = 2.4 (+/- 0.2) X 10(4)M-1. These values agree reasonably well with that reported in the literature for Ricinus agglutinin 1. The number of binding sites obtained by the different experimental procedures is 1.94 +/- 0.1 per molecule of 120 000 daltons and is equal to the reported value of 2. The consistency in the values of Ka and number of binding sites indicate the absence of additional subsites on Ricinus agglutinin 1 for its specific sugars. In addition, the excellent agreement between the binding parameters obtained by equilibrium dialysis and fluorescence polarization indicate the potential of ligand-fluorescence-polarization measurements in the investigation of lectin-sugar interactions.

Binding Sites↗
PubMed1982

The surface glycoproteins of human skin fibroblasts detected after electrophoresis by the binding of peanut (Arachis hypogaea) agglutinin and Ricinus communis (castor-bean) agglutinin I.

A new methodology was developed to study the cell-surface glycoproteins of cultured human skin fibroblasts. This was based on the binding of a variety of biotinyl-lectins to nitrocellulose electrophoretic transfers of total fibroblast lysates after separation in sodium dodecyl sulphate/polyacrylamide gels, followed by reaction with avidin-biotinyl-peroxidase complexes and detection with 3,3'-diaminobenzidine. The technique proved to be very sensitive and a large number of glycoproteins were detected by binding of concanavalin A and wheat-germ agglutinin. Binding of peanut agglutinin and to a lesser extent of Ricinus communis agglutinin I were found to be dependent on prior removal of sialic acid residues from the glycoproteins. Since by treatment of intact viable cells with neuraminidase only external sialic acid residues were removed, peanut agglutinin and Ricinus communis agglutinin I could thus be utilized for selective detection of cell-surface glycoproteins. Also, because peanut agglutinin was known to bind preferentially to oligosaccharides of the O-glycosidic type, and Ricinus communis agglutinin I to those of the N-glycosidic type, the two lectins were complementary in displaying the surface glycoproteins and in providing information about their oligosaccharide composition.

Arachis↗
PubMed1980

Purification and physicochemical properties of ricins and agglutinins from Ricinus communis.

Two toxin ricins and two agglutinins have been purified from the seeds of Ricinus communis by an improved procedure based on ion-exchange chromatography and gel filtration. One of the two purified ricins binds to Sepharose 4B while the other does not. The physicochemical properties of the four Ricinus lectins are presented and the possible relationships of these Ricinus lectins to those previously described are discussed.

Amino Acids↗
PubMed1994

IFN-gamma IL-2, and IL-4 mRNA expression in the skin and draining lymph nodes of BALB/c mice repeatedly infested with nymphal Ixodes ricinus ticks.

The skin and draining lymph nodes of BALB/c mice were examined for IFN-gamma, IL-2, and IL-4 mRNA expression by in situ hybridization in three successive infestations with nymphal Ixodes ricinus ticks. IFN-gamma and IL-2 mRNA positive cells were readily detected in lymph node sections during primary antigenic stimulation (72 hr post-tick attachment), whereas hybridization with IL-4 probe yielded no or only a faint positive signal. No changes in the cytokine pattern were observed in lymph node sections from reinfested mice, with IL-4 mRNA always being expressed to a lesser extent than IFN-gamma and IL-2 mRNA. Seventy-two hours post-tick attachment in primary infestation, some infiltrating cells in the skin were positive for IFN-gamma and IL-4 mRNA, but not for IL-2 mRNA. In skin sections of reinfested mice, mRNA coding for IFN-gamma, IL-2, and IL-4 were detected in infiltrating cells. Cells positive for IL-4 mRNA were lower in number than those positive for IFN-gamma and IL-1 mRNA. A significant decrease in the number of IL-4 mRNA positive cells in the tertiary infestation was noted. All together, these results indicate that I. ricinus nymphal ticks antigens are able to elicit expression of IFN-gamma, IL-2 mRNA and to a lesser extent IL-4 mRNA in both skin and draining lymph nodes. In addition, repeated infestations with ticks led to strong expression of IFN-gamma and IL-2 mRNAs in the skin that may be correlated with previous observations showing the occurrence of cutaneous delayed-type hypersensitivity in tick-infested mice. Notably, the cytokine pattern observed in the skin and draining lymph nodes is not associated with a protective immune response in mice against I. ricinus nymphal ticks infestations.

Animals↗
PubMed2000

Rotavirus infection of MA104 cells is inhibited by Ricinus lectin and separately expressed single binding domains.

Various lectins were tested for blocking rotavirus infection of MA104 cells and it was observed that galactose-specific lectins were the most inhibitory. Of these Ricinus agglutinin was able to inhibit infection (by human and animal strains) at concentrations as low as 10(-9) M. In addition, in a virus overlay protein blot assay Ricinus agglutinin competed with simian rotavirus SA11 for binding to solubilized MA104 proteins. Amino acid sequence comparisons revealed similarity between the ricin toxin B subunit (which contains two separate carbohydrate-binding motifs: single binding domains (SBD) 1 and 2) and rotavirus spike protein VP4. A filamentous phage display system was used to independently express the two binding domains and while SBD1 inhibited infection of MA104 cells by CRW8, NCDV, and to a lesser extent Wa, SBD2 blocked only CRW8 and NCDV infection. Furthermore inhibition of CRW8 infection was a direct result of phage inhibiting virus attachment to cells. When amino acid 248 within SBD2 was mutated from the ricin toxin to the Ricinus agglutinin sequence this phage clone showed reduced binding to galactose and was no longer able to inhibit virus infection. Thus, rotavirus recognizes galactose as an important component of the receptor on MA104 cells.

Amino Acid Sequence↗
PubMed1996

Identification of four genomic groups of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks collected in a Lyme borreliosis endemic region of northern Croatia.

We investigated the presence of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks collected in a Lyme borreliosis (LB) endemic region of northern Croatia. Ticks (n = 124) were collected at five locations and analysed by the polymerase chain reaction (PCR). A DNA fragment from the internal transcribed spacer (ITS2) of I. ricinus was detected in all tick lysates, indicating that PCR inhibitors were not present. Borrelia burgdorferi sensu lato DNA was detected in 56 out of 124 ticks (45%). Four genomic groups were identified: Borrelia afzelii (n = 26), Borrelia garinii (n = 5), group VS116 (n = 5) and B. burgdorferi sensu stricto (n = 1). Mixed infections of B. afzelii with group VS116 (n = 10) and B. afzelii with B. burgdorferi sensu stricto (n = 1) were also detected. Eight ticks contained B. burgdorferi sensu lato, which could not be typed. The detection of B. afzelii and B. garinii in ticks was in agreement with manifestations of LB found locally. The occurrence of group VS116 in northern Croatia and in an earlier study in The Netherlands, infers that this genomic group may be well established in European I. ricinus.

Animals↗
PubMed1995

Differences in Borrelia infections in adult Ixodes persulcatus and Ixodes ricinus ticks (Acari: Ixodidae) in populations of north-western Russia.

Dark-field microscopy was used to determine the number of Borrelia spirochetes in 630 standard preparations obtained from adult ixodid ticks (344 Ixodes persulcatus and 286 I. ricinus) collected in 1989-92 in the Leningrad region of Russia. The average numbers of Borrelia in I. persulcatus and I. ricinus preparations were 34.7 and 23.3 per 100 microscopic fields, respectively. The maximal individual values registered each year for ticks of both species were several hundred times greater than the minimal values. Ticks carrying relatively small numbers of Borrelia generally predominated. Proportions of more heavily infected ticks varied considerably from year to year. These parameters were significantly higher in foci with predominance of I. persulcatus ticks. As a consequence, risk to acquire Lyme borreliosis in such foci is considered greater than in foci where I. ricinus predominates.

Animals↗
PubMed1994

Infection rates of Borrelia burgdorferi in different instars of Ixodes ricinus ticks from the Dutch North Sea Island of Ameland.

Between 1988 and 1993, a total of 7173 I. ricinus ticks, predominantly, were collected from the vegetation on the Dutch North Sea Island of Ameland. A proportion of the ticks (n = 547) was screened for the presence of Borrelia by immunofluorescence. Infection rates of Borrelia varied, in nymphs (n = 347) from 13% to 46% and in adults, (n = 122) from 20% to 43%. The infection rate in larvae (n = 84) collected in 1993 was 21%, showing that transovarial transmission of B. burgdorferi occurs in the I. ricinus population on Ameland. Two tick-naive sheep seroconverted for B. burgdorferi after field-collected adult or nymphal I. ricinus were allowed to feed on them. Larval progeny (n = 168) of 15 female adult ticks fed on one of these sheep were free from B. burgdorferi. B. burgdorferi was isolated in culture from field-collected adult ticks. Serotyping using monoclonal antibodies against outer surface proteins A and C indicated that both isolated belonged to genospecies B. garinii, and this was confirmed by DraI restriction analysis of the variable DNA sequence between the 5S and 23S rRNA genes.

Animals↗