S. VELEBNÝ, G. HRČKOVÁ, O. TOMAŠOVIČOVÁ, P. DUBINSKÝ
Parasitological Institute of SAS, Hlinkova 3, 040 01 Košice, Slovak Republic, E-mail: email@example.com
Liposomal preparations of fenbendazole (FBZ) with nega-tive surface charge (negat. lip. FBZ) and without charge (neutr. lip. FBZ) as well as liposomized glucan (lip. glu-can) were prepared. Size distribution analysis showed that 73.97 % negat. lip. FBZ, 73.20 % neutr. lip. FBZ and 85.13 % lip. glucan comprised of particles smaller than 1.1 µm in diameter. Formulations of FBZ were administered orally (p. o.) and subcutaneously (s. c.) to mice experimentally infected with Toxocara canis at a dose rate 25 mg.kg-1 of body weight twice daily for five days from the day 28 post infection. Efficacy of the drug was evaluated by larval count in mus-cles and in the brain on day 30 after treatment. Significant enhancement of the efficacy on Toxocara lar-vae in the brain was recorded with both orally administered liposomal formulations of FBZ (20.3 and 24.3 % - contrary to 0 % of the free drug). Only negat. lip. FBZ was signifi-cantly more effective on larvae in muscles (44.9 % - con-trary to 27.4 % with the free drug). Liposomal preparations of FBZ were significantly more ef-fective on larvae in muscles after s.c. administration (55.7 and 48.3 %, resp.) than after the oral route (44.9 and 22.8 %, resp.). Efficacy of these preparations on larvae in the brain was significantly improved only with neutr. lip. FBZ (44.7 %) comparing to the oral route of the same drug for-mulation (24.3 %) and also in comparison with s. c. admi-nistered negat. lip. FBZ (25.8 %). The highest efficacy of liposomal preparations of FBZ was achieved after their combined administration with lip. glucan: negat. lip. FBZ 56.1 %, neutr. lip. FBZ 56.8 % on larvae in muscles; 42.2 and 59.1 %, resp. on larvae in the brain.
Experiments were carried out on male Balb/c mice and ma-crophages obtained from the peritoneal cavity. The Candida cells (Candida albicans L 45) were killed by heat - treatment and opsonized with mouse serum. Phagocytosis was assessed by incubation 0.1 ml of macrophages with the Candida suspension and microscopic slides with cell smear were prepared. The phagocytic capacity and percen-tage of phagocytizing macrophages were calculated. It was found that infection with Trichinella pseudospiralis or Trichinella spiralis caused a significant reduction in the phagocytic capacity and in the percentage of phagocitizing macrophages. A similar effect was also observed when normal mice were inoculated with the extract of the lipid fraction from Trichinella spp., containing prostaglandins. Treatment with inhibitors of prostaglandin synthesis: indo-methacin or acetylsalicylic acid abolished this effect. The-se findings suggest that immunodepression during infe-ction with Trichinella spp. may be mediated by the meta-bolites of arachidonic acid cascade, partially of parasite origin.
V. Barus, F. Tenora1, S. Kracmar1 Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Kvetná 8, 603 65 Brno, Czech Republic; 1Mendel University of Agriculture and Forestry, Zemedelska 1, 613 00 Brno, Czech Republic; E-mail: firstname.lastname@example.org
The four parasite-host systems (adult tapeworms vs. birds) were analysed by atomic absorption spectrometry for lead and cadmium concentrations. The Pb and Cd concentra-tions in the parasite biomass (species Ligula intestinalis, Confluaria capillarioides, Mesocestoides perlatus, and Cladotaenia globifera) were compared with those found in different tissues (muscle and liver) of their final host (Pha-lacrocorax carbo, Podiceps cristatus, Accipiter gentilis, and Buteo buteo). In all parasite-host systems studied, the ability of adult tapeworms to accumulate different concen-trations of heavy metals (Pb and Cd), was greater than that of their final host tissues. The ratio values for Pb in mus-cles of hosts varied between 2.38-5.95, for liver tissue bet-ween 1.19-10.07. For Cd the same ratio varied in muscles between 1.14-12.33, in liver tissue between 1.43-10.57. The highest concentrations of Pb and Cd were found in the strobila of the tapeworm C. globifera parasitizing in B. buteo. The results are discussed in detail and compared with the data published hitherto on the accumulation of heavy metals in parasites of fishes and mammals.
Department of Zoology, Faculty of science, Minia University 61519, EL-Minia, Egypt; E- mail: email@example.comSummary
The variability of 25 morphometric features and 6 indices for both metacercaria and adult Diplostomum tregenna Nazmi Gohar, 1932 are introduced in this study. Examina-tion by scanning electron microscopy supplemented new details. The ventral surface of the metacercariae, but not the dorsal, showed sensory papillae and the entire body surface was devoid of tegumental spines. A composite map of papillae distribution pattern on the ventral surface is in-troduced. The dorsal surface of the adult was regularly ar-ranged with dentate spines except for its last fifth. Tegu-mental spines on the ventral surface were restricted to a-reas around the ventral sucker and Brande's organ.
K. TAIRA*, H. YOSHIFIJI1, N. TAIRA2Nippon Veterinary and Animal Science University, Musashino, Tokyo 180-0023, Japan; E-mail: firstname.lastname@example.org; 1 Kanazawa-shi Meat Inspection center, Kanazawa, Ishikawa 921, Japan; 2 National Institute of Animal Health, Kannondai, Tsukuba, Ibaraki 305-0856, Japan
A comparative study on the dynamics of Fasciola faecal egg counts (EPG) in cattle and in goats was conducted for an extended observation period. Two calves were dosed with 1 000 metacercariae (MC) of F. gigantica (Japanese strain) and two kids with 50 MC.Until patency EPG counts were carried out in weekly in-tervals and afterwards daily until necropsy of the calves 147 and 390 days after infection (DAI) and necropsy of kids at 132 and 732 DAI, respectively. Initial appearance of eggs in the faeces occurred 80 and 81 DAI in the calves and 64 and <70 DAI in the kids. The highest EPG in the calf was 1.087 at 181 DAI and in the kid 697 at 129 DAI. Thereafter, the EPG in the calf gradually decreased to 5 EPG at 328 DAI. On the other hand, the EPG value in the kid persisted at a comparatively high level until 732 DAI.
M. C. Dolezel, D. W. T. Crompton1University of Vienna, Institute of Zoology, Department of Limnology, Althanstraße 14, 1090 Vienna, Austria, E-mail: email@example.com; 1Division of Environmental and Evolutionary Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK Summary
In Scotland two populations of powan, Coregonus lavare-tus (L.), harbour plerocercoids of Diphyllobothrium den-driticum and D. ditremum (Cestoda), whereas only one po-pulation is infected with metacercariae of Cotylurus erra-ticus (Trematoda). The present study was undertaken to describe differences of parasite occurrence and abundance as well as to elucidate effects of the parasites on fish con-dition and heart size. The number of encysted parasite sta-ges and the weight of gonads, livers and hearts were deter-mined. Lengths and widths of histological sections of the heart ventricle and the bulbus were measured. Adverse ef-fects of combined (cestode and heavy trematode) parasite burdens on the general condition and of trematode infe-ction on liver and fecundity can be confirmed for female powan. Heart measurements were largely unaffected. The hypothesis that a parasite induced alteration of the heart function could decrease the escape response of the fish could not be supported.
Department of Pure and Applied Biology University of Leeds, Leeds LS29JT, UK
Cyathocephalus truncatus procercoids harboured in the bo-dy cavity of Gammarus pulex for over one year of infec-tion were seen structurally to be fully matured and produ-ced viable eggs. The eggs were found to develop to infecti-ve oncospheres in 24 days when cultured at 25°C. Young specimens of G. pulex were infected with the oncospheres and the early procercoids of the infection also develop to mature ones in 3 months thus establishing the life cycle of the tapeworm using only G. pulex as the host. The amphi-pods were found to harbour the mature procercoids for o-ver one year six months and also produced eggs, which were infective to other amphipods. A monoxenous life cyc-le of the trapeworm with the amphipod, G. pulex as the on-ly host is an advancement of neoteny demonstrated in the Spathebothriidae group.
M. Ziolkowska, M. Chibani1, A. Kijewska, J. RokickiDepartment of Invertebrate Zoology, Univ. Gdańsk, Al. Pilsudskiego 46, 81 378, Gdynia, Poland, E-mail: firstname.lastname@example.org; 1Marine Biology Centre Polish Academy of Sciences, Św. Wojciecha 5, Gdynia, Poland
576 flounders were collected from the Pomeranian Bay, Gulf of Gdańsk and the open sea off Łeba in the period from March 1997 to February 1999. 105 flounders were collected in October 1999 from Lake Łebsko. 143 out of 681 fish were infected. 1557 acanthocephalans of Pom-phorhynchus laevis were recovered. The mean intensity of infection and prevalence were calculated. One can conclu-de that the intermediate host Gammaridae plays a signifi-cant role in the occurrence of P. laevis, and thus in the pre-valence and intensity of infection. The age of the fish and the occurrence of P. leavis were correlated. Young fish, no older than one year, were infected by P. leavis. Three- and four-year-old fish were the most susceptible to infection. Older fish, aged five years or more, were less susceptible. Only one encapsulated acanthella was found on the go-nads; there was therefore a possibility that Platichthys flesus could act as a paratenic host. In the Skagerrak or in the north-western Baltic Sea P. laevis commonly occurs in the form of encapsulated larvae. This life cycle strategy is probably due to the presence or absence of predators of P. flesus and the final host of P. laevis.
P. Cakic, Z. Petrovic*, D. Kataranovski, D. Jakovcev, M. LenhardtInstitute for Biological Research, 11060 Belgrade, Yugoslavia, E-mail: email@example.com; *Faculty for Veterinary Medicine, University of Belgrade, Yugoslavia
Oligochaeta Chaetogaster limnaei has been described in the literature exclusively as a commensal or semi-parasitic species inhabiting mantle cavities, pulmonary and kidney tissues of many freshwater genera of the Pulmonata (Gas-tropoda). During our studies the parasite was detected on the body of beluga fry (Huso huso, Acipenseridae, Pisces). Apart from its record on the new host, it is important to point out that this parasite provoked injuries of the beluga fry epithelia by its mouth apparatus. Small wounds appeared on contact spots leading the fry to an extinction. Therefore, it is our assumption that this is the first record of Chaetogaster lim-naei as ectoparasite on the fry of beluga, which has not been described in the literature so far.
M. Ivezic, E. Raspudic, M. Brmez University of J. J. Strossamyer, Faculty of Agriculture Osijek, Trg sv. Trojstva 3, 31000 Osijek, Croatia; E-mail: firstname.lastname@example.org
Nematode community structure was analyzed in four dif-ferent agroecosystems in order to determine how differen-ces between crops and tillage treatment can influence ne-matode communities. The greatest total number of nematodes and greatest num-ber of genera occurred in alfalfa. Significant differences in total number of nematodes occurred just in alfalfa compa-red to the other three treatments, and very significant dif-ferences in number of genera, also just in alfalfa. The lo-west total number of nematodes and the lowest number of genera were determined in sugar beet. Trophic structure was similar in all treatments – dominated by bacterivorous and plant parasitic nematodes. Predators was the least pre-sent group in all treatments. Maturity index, Plant parasitic index and PPI/MI were calculated and there were no sig-nificant differences between MI and PPI/MI between the treatments. We can conclude that nematode community structure was most disturbed in sugar beet and in corn, which are both row crops with considerable impact of tillage on nematode communities. The lowest influence of tillage was in alfalfa, which is perennial crop where the nematode communities were less disturbed.