Ticks of the province of Salamanca (Central/NW Spain)

By sporadic examination of 492 wild animals and regular weekly checks of dogs (179), cattle (288) and sheep and goats (141), 13 Ixodides were identified in the province of Salamanca. Some of these were only detected on the northern (I. ricinus) or southern (H. lusitanicum and B. annulatus) slopes of the mountains to the south of the province. Except for occasional introductions, H. lusitanicum and B. annulatus are not found on the Castillian plateau. In wild animals, 12 species were found of which only 4 are monotropic for some of these animals. In dogs, the most important species were R. turanicus and R. sanguineus. The latter shows only one generation per year and its nymphs are held to be the most important vector for the cases of boutoneuse fever registered in the provincial setting. In cattle, R. bursa is the most important tick, in terms of its prevalence in June/July (adults) and from November to January (immature forms). It also displays a much higher parasitization intensity than that of any of the other 7 species found on cattle. These remaining tick species (D. marginatus, H. marginatum, H. lusitanicum, I. ricinus, R. turanicus, Hae. punctata and B. annulatus) are abundant when R. bursa is absent ; that is, in spring and at the end of summer, which thus are periods of richness in Ixodides but of low parasitism intensity. The ticks found on sheep and goats are the same as those detected on cattle, but in some of them prevalence and intensity vary as result of the kind of pasture frequented by the ovine and caprine hosts

Antigens of interest for the diagnosis of parasitism in pigs by Ornithodoros erraticus and Ornithodoros moubata

8 pages.-- PMID: 9379286 [PubMed].We show by sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blot that the composition of the soluble extracts of salivary glands (SGE-2) of Ornithodoros erraticus and Ornithodoros moubata is similar to that of the saliva (pilocarpine-induced), and that the extracts are a valid source of antigens for the detection of anti-argasid antibodies. It is also shown that the SGE-2s do not vary qualitatively with the developmental stage, physiological status, or sex of the ticks. The antigenic components (at least in O. erraticus) are released into the SGE-2 by the action of enzymes that can be inhibited by phenylmethane sulfonyl fluoride plus EDTA. Most of the components of the SGE-2, except the antigenic ones, are strongly glycosylated. Accordingly, the deglycosylation of the SGE-2s does not affect the recognition of antigenic components by anti-tick sera. In both species, the major components of the SGE-2s or the saliva are not recognized by the corresponding antisera. These nonimmunogenic components could have vaccinal value but not diagnostic interest. Finally, it is shown that the antigens of O. erraticus and O. moubata do not cross-react with one another and that those of the first species are more antigenic than those of the second.Peer reviewe

Leishmaniasis in the province of Salamanca, Spain. Prevalence in dogs and seasonal dynamics of vectors

Of 433 dogs examined in 4 natural zones of Salamanca Province, Spain, the prevalence of canine leishmaniasis (IFAT titres ≥ 1/80) was 0-3 % in most mountain villages and from the Castillian plateau (> 600 m. a. s. 1.) and 10-15 % in villages situated on hillsides (« flanc du coteau ») with elevations < 600 m. a. s. 1. An exception was the high prevalence found in the area around the city of Salamanca owing to its height (800 m. a. s. 1.) and flood-plain situation. Of 5,105 sandflies captured with sticky traps, P. perniciosus and P. ariasi were well represented at the sites with high prevalences of canine leishmaniasis but not elsewhere. Their abundance in the periurban area of the city of Salamanca is attributed mainly to human transformation of the environment. Of the two species, only with P. ariasi can a linear relationship be observed between density and the prevalence of canine leishmaniasis, which seems to show that in Salamanca P. ariasi is its main vector. The probable lower observed vectorial capacity of P. perniciosus could be due to the fact that no progressive physiological ageint towards the end of the summer was observed. Patients with leishmaniasis in the Province come from sites with the highest prevalence of canine leishmaniasis

Host immune response evasion strategies in Ornithodoros erraticus and O. moubata and their relationship to the development of an antiargasid vaccine

10 pages.-- PMID: 9347516 [PubMed].We analysed in mice why the salivary gland extract (SGE-2) from Ornithodoros erraticus and O. moubata induce a protective response with Freund's adjuvants (FAs) in swine while the saliva, in natural conditions, does not. Such protection has been ascribed to the fact that administration of SGE-2 plus FAs permits the recognition of certain salivary components that under natural conditions are not immunogenic. The present findings confirm this hypothesis since in mice, which are unable to recognize the above components, the SGE-2-FAs do not induce any protection. We rule out the possibility that the cause of this could lie in the absence of prostaglandin E2 in the SGE-2 (vs saliva) since it is not present in either fluid. Neither could it be due to a change in antibody isotype since those induced by parasites bites and by the SGE-2-FAs are the same (IgG2a > IgG1 > IgG2b; not IgG3, IgM, IgE). No IgG2a were seen when the SGE-2 were administered alone or with alum or ricin. It is therefore suggested that first responses would be Th1 and the second ones Th2, although no IgE is seen in the latter responses either. The parasites do not require complement to feed; by contrast, they block its activation and skin cellular infiltrates, such as those elicited by IL-8, MCP-1 and C5a, do not affect them, regardless of the presence or not of antitick antibodies.Peer reviewe

Purification, N-terminal sequencing and diagnostic value of the major antigens of Ornithodoros erraticus and O. moubata

14 pages, 3 figures, 3 tables.-- PMID: 10622611 [PubMed].-- Available online on Nov 15, 1999.To enhance the specificity and sensitivity of serological detection of swine exposed to Ornithodoros erraticus or O. moubata, we purified the 158, 186, 215 and 260 kDa antigens from the former species and the designated (owing to their MW and charge) 19C, 17A, 20A1 and 20A2 antigens of the latter by HPLC and gel electroelution methods. All the O. erraticus antigens share epitopes and are difficult to purify individually by reverse phase and ion-exchange chromatography due to their molecular similarity. Tested individually by ELISA, all of them give the same optical densities (OD) with anti-O. erraticus sera, and these ODs are always lower with anti-immature than with anti-adult sera. Although immature and adult specimens have the same antigens, immature forms induce more anti-carbohydrate antibodies than adults. This is the reason for the lower ODs of the anti-immature sera against purified antigens, since these latter antigens essentially react with anti-peptide antibodies (hence, increasing the specificity and sensitivity of the serology). The N-terminus of the 260 kDa antigen shows 80–90% similarity with the hemoglobin α-chain of many mammals. The antigens of O. moubata are proteins that are very different from one another and are, therefore, readily purified by ion exchange chromatography. The 20A1 antigen appears to be the most immunogenic and is recognized equally by anti-immature and anti-adult sera. This antigen does not give false positive reactions with the negative control sera analyzed and its N-terminus region shares 46.2% homology with the α-chain of the C3 component of rabbit complement.This work was supported by grants EEC no. AIR3-CT93-1332 and CICYT no. AGF96-1092.Peer reviewe