Since the expulsion of Trichinella spiralis worms is a do-se-dependent effect, to assess whether or not intestinal in-traepithelial lymphocytes (i-IELs), particularly T cells, respond comparably to different sized T. spiralis infection, we used C57BL mice, orally infected with two doses, 50 or 400 viable T. spiralis muscle larvae (L1).In the present study we found that the appearance of T cells preceded that of T cells among i-IELs of infected mice. The proportion of T cells increased promptly (on day 1 p. i.) and significantly (P 0.005) in the gut epi-thelium of mice infected with 400 L1 T. spiralis larvae, but not in mice infected with 50 L1 larvae, compared with uninfected mice. These data indicate that T cell respon-ses varied in a dose-dependent manner. In spite of their rapid increase, no correlation between kinetics of nor T cells in i-IELs and T. spiralis worm expulsion was observed in mice infected with either 400 (because of a ra-pid decrease in the i-IEL population in gut epithelium early after activation, by day 7 p. i.) or 50 L1 larvae (since no statistically significant rise in the proportion of or T cells was observed during the course of infection). All-together, our results suggest that both T. spiralis infection levels probably elicit immunodepression by interference with the first line defence of T cell function thereby influencing the outcome of experimental T. spiralis gut infection.
S. Velebny, G. Hrckova, O. TomasovicovaParasitological Institute SAS, Hlinkova 3, 040 01 Kosice, Slovak Republic, E-mail: email@example.com
Fenbendazole or albendazole entrapped in liposomes sta-bilised with poly(ethylene glycol) (stab.lip.FBZ), (stab.lip. ABZ) as well as conventional negatively charged liposo-mes with entrapped immunostimulator glucan (lip.glucan) were prepared. Liposomal formulations of FBZ and ABZ were subcutaneously administered to mice experimentally infected with Toxocara canis eggs at a dose of 25 mg.kg-1of body weight twice a day for five days from day 28 post infection. Drug efficacy was evaluated by larval counts in muscles and in the brain on day 30 after the last dose. Efficacy of stab.lip.FBZ and ABZ on T. canis larvae in muscles of mice was similar (73.6 % and 68.2 %, respectively) and increased after subcutaneous co-administration of lip.glucan (91.1 % and 70.0 %, resp.). In the brain, stab. lip.FBZ was significantly less effective than stab.lip.ABZ (45.8 % and 88.0 %, respectively). Co-administration of liposomised glucan significantly increased antitoxocaral effect of both anthelmintics (58.1 % - stab.lip.FBZ, 92.2 % - stab.lip.ABZ). These results showed the important role of the stabilised liposomes as well as immunostimulator glucan in the enhacement of the larvicidal efficacy of the anthelmintics on T. canis larvae and confirmed higher effi-cacy of ABZ than FBZ on larvae in the brain.
E. Dvorožňákova, Z. Borosková, P. Dubinsky, O. Tomasovicova,B. Machnicka1Parasitological Institute of the Slovak Academy of Sciences, Hlinkova 3, 040 01 Kosice, E-mail: firstname.lastname@example.org; 1Institute of Parasitology of the Polish Academy of Sciences, Twarda str. 51/55, 00-88 Warsaw, Poland
The proliferative response of spleen T and B lymphocytes, the percentage of CD4+ and CD8+ T cells and the produc-tion of immunoglobulin subclasses of specific antibodies were studied in mice after their infection with eggs and im-munization with the excretory-secretory larva antigen of Toxocara canis. The proliferative activity of T and B lym-phocytes in mice C57BL6 was assessed spectrophotome-trically, T subpopulation numbers were evaluated by flow cytometry and specific antibodies were detected by the ELISA method. The infection elicited long-term stimulation of the prolife-rative response of T and B cells. Re-infection significantly increased the activity of these cells. Though there was a ra-pid increase in the proliferative response of T-cells after mouse immunization, re-immunization caused its decrease. B lymphocytes responded more intensively after reimmunization than after immunization. The infection caused a decrease in CD4+ T-cells only up to day 21 of the experiment, followed by an increase. In comparison with the CD4+ cell population, the percentage of CD8+ T-cells was not influenced up to day 21 of the experiment. Re-infection significantly reduced the representation of both subpo-pulations of T-cells. Immunization caused a long-term in-hibition of the percentage occurrence of both the subpopu-lations for the duration of the experiment and, moreover, re-immunization enhanced this decrease. The infection eli-cited a significantly increased production of immunoglo-bulin IgG1and IgG2 subclasses, with IgG2 dominancy and with an increase in both the subclasses after the reinfec-tion. The immunization and re-immunization did not indu-ce the production of IgG1 but even the production of IgG2 was very low. The results indicate that after the infection, when a host bo-dy is exposed to the influence of various larval antigens, its immune response is more intensive than after its re-immunization with the excretory-secretory antigen alone.
To estimate the intestinal eosinophil cell responses in a pa-ratenic host of the nematode Ascaris suum, lambs were in-fected orally with 1000 infective Ascaris suum eggs at day 0 of the experiment. The small intestine of control and in-fected lambs was examined histologically. Data obtained showed a higher number of intestinal eosinophils in infected lambs compared with controls. The increase of intesti-nal eosinophils coincided with the appearance of A. suum larvae in intestinal tissues at day 14 after infection. On day 21 of the experiment the highest incidence of A. suum lar-vae was reported. Thereafter no larvae could be detected, while a marked and uniform increase of intestinal eosino-phils was evident. The peak numbers of eosinophil cells was at day 35. At the end of the experiment a decline of eosinophil numbers was associated with no or a low inci-dence of A. suum larvae. The uniform increase of intestinal eosinophil numbers, in the absence of parasitic larvae from the small intestines of infected lambs, suggested that these cells seem to be a measure of general immune response of the host rather than an indication of helminthosis.
M. Sarkunas1,2, P. Nansen2, J. W. Hansen3, A. Malakauskas1,2
1 Department of Infectious Diseases, Lithuanian Veterinary Academy, Tilzes 18, LT-3022 Kaunas, Lithuania, E-mail: email@example.com; 2 Danish Centre for Experimental Parasitology, The Royal Veterinary and Agricultural University, Ridebanevej 3, DK-1870, Frederiksberg C, Denmark; 3 Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalla, 00100 Rome, ItalySummary
The present experiment, conducted over two consecutive grazing seasons, was designed to evaluate the effect of strategic ivermectin treatments on parasitism and perfor-mance of calves reared in permanent summer-camp sys-tems. Permanent summer-camp systems are characterised by having small outdoor pens with a hut in which the calves are fed a full diet comprised of fresh cut grass, concentrate, skimmed milk and water ad libitum. Twenty heifer-calves (3-5 months of age) were divided into two comparable groups according to live weight. Calves in group A were treated with ivermectin (200 g/kg) at weeks 3-8-13 after turnout, while group B served as an untreated control group. The herbage larval counts and infectivity level were monitored by analyzing grass samples and using parasite naive tracer calves in October. The results showed that strategic ivermectin treatments, given to first-season calves at week 3, 8 and 13 after turnout effectively prevented build-up of high numbers of larvae on the grass du-ring the grazing season. The effect of treatments was clear-ly reflected in the differences between worm burdens of the tracer calves. During the following grazing season, both groups were grazed in a single herd. In the start of the second grazing season the treated calves gained on average 32 kg more than the control animals. The difference in weight gains remained until the end of the grazing season. No incidence of loss producing infections was observed during the second-grazing season.
HELMINTHOLOGIA, 37, 4:215-217, 2000Cucullanus mexicanus sp. n. (Nematoda: Cucullanidae) from the intestine of the freshwater catfish Rhamdia guatemalensis (Pimelodidae) in Mexico
J. M. CASPETA-MANDUJANO1,2, F. MORAVEC2, R. AGUILAR-AGUILAR31Centre for Biological Research, Autonomous University of Morelos State, Av. Universidad No. 1001, Col. Chamilpa, C.P. 62210, Cuernavaca, Morelos, Mexico; 2Institute of Parasitology, Academy of Sciences of the Czech Republic, Branisovska 31, 370 05 Ceské Budejovice, Czech Republic, E-mail: firstname.lastname@example.org; email@example.com; 3Institute of Biology, National Autonomous University of Mexico, A.P. 70-153, 04510 Mexico, D.F., Mexico
A new cucullanid nematode, Cucullanus mexicanus sp. n., is described from specimens recovered from the intestine of the freshwater catfish Rhamdia guatemalensis (Günther) (Pisces, Pimelodidae) from three localities (brooks El Sal-tillo, Valle Nacional and San Juan Bautista) in the State of Oaxaca, central Mexico.The new species, belonging to the subgenus Cucullanus, distinctly differs from all its congeners in having an unu-sually large, conspicuously elongated precloacal sucker and only one pair of preanal papillae near it; it is further characterized by almost equal spicules (length 330-356 m), a small Y-shaped gubernaculum, and by the distri-bution of caudal papillae in the male. Cucullanus mexica-nus sp. n. is the second freshwater species of the genus re-ported from Mexico.
HELMINTHOLOGIA, 37, 4:219-222, 2000Morphological differentiation of Oesophagostomum dentatum and O. quadrispinulatum in pigs after experimental infection
M. VARADY, J. CORBA
Parasitological Institute, Slovak Academy of Sciences, Hlinkova 3, Kosice 040 01, Slovak Republic, E-mail: firstname.lastname@example.org
Oesophagostomum dentatum and O. quadrispinulatum we-re obtained as pure isolates from 10 infected pigs. For mor-phometric characterisation 250 male and 250 female worms of each species were cleared in lactophenol and examined microscopically. The identification of species was based on 4 characteristics: the shape of buccal capsule, the structure of the oesophagus, the length of the spicules in male worms and the length from the anus to the tip of the tail in female worms.In the buccal capsule in O. quadrispinulatum it could be seen that its sides are not parallel as in O. dentatum. The commencement of oesophagus has swollen sides and is almost globular in outline whereas in O. dentatum the sides of the corresponding region are practically parallel. The same was seen in the posterior region of the oesophagus. The whole structure of the oesophagus in O. quadrispinu-latum may be described as vase-shaped compare to a club-shape in O. dentatum. The spicules of O. quadrispinulatum males are considerably shorter with an average compared to O. dentatum. The tail of female O. quadrispinulatum is much longer and tape-ring than that of O. dentatum.
HELMINTHOLOGIA, 37, 4:223-228, 2000Faunistic and ecological trends on the helminthic community of Genetta genetta Linnaeus, 1758 (Carnivora: Viverridae) in the Iberian Peninsula
J . C. Casanova*, C. Feliu, J. Miquel, J. Torres, M. Špakulová1Laboratori de Parasitologia, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain; E-mail: email@example.com; 1Parasitological Institute, Slovak Academy of Sciences, Hlinkova 3, 040 01 Košice, Slovak Republic, E-mail: firstname.lastname@example.org
The helminth fauna of the genet (Genetta genetta Linnae-us, 1758) was studied in detail from 299 individuals com-ing from 85 localities of the Iberian Peninsula. Most of the genet's helminth species are stenoxenous (show a narrow host specificity) and have probably been introduced to the Iberian Peninsula together with their host in historical ti-mes. The composition of these species does not practically differ from the genet's helminths in the original North Af-rican area. Several other helminth species of a low spe-cificity are shared at genet and other Iberian carnivores. Factors of the genet's ethology, chorology, and diet affect-ing the structure and dynamics of the helminthic commu-nity were discussed.
HELMINTHOLOGIA, 37, 4:229-232, 2000Helminth fauna of the Argentine conger, Conger orbignyanus (Pisces: Anguilliformes)
R. D. TANZOLA, S. E. GUAGLIARDO
Catedra de Parasitologia, Departamento de Biologia, Bioquimica y Farmacia, Universidad Nacional del Sur, (8000) Bahia Blanca, Republica Argentina; E-mail: email@example.com.
The helminth fauna of Conger orbignyanus was analyzed. The species richness and specific diversity of parasites we-re statistically studied by using non-parametric tests. Ten species of helminths were found in 81 adult congers: 8 of them were previously cited in Porichthys porosissimus from the same area, the estuary of Bahía Blanca, Argenti-na. More than 80 % of the 2052 individuals recovered were at larval stage and belonging to the following taxa: Grillotia erinaceus, Scolex pleuronectis type 1 and 2, Coryno-soma hammani, C. australe, Contracaecum sp., Terranova sp. As previously observed in P. porosissimus, the trypa-norhynch G. erinaceus was dominant in the helminth com-munity. The community of intestinal helminths comprise 5 taxa: Prosorhynchus australis, Cucullanus sp., Stomachi-cola sp., and S. pleuronectis type 1 and 2. All of the species component were distributed in an overdispersed man-ner. Regarding both the whole assemblage of parasite spe-cies and the intestinal ones, the helminth communities of C. orbignyanus are characterized by low values of both species richness and diversity.The specific diversity was found positively correlated with the size of the hosts.
HELMINTHOLOGIA, 37, 4:233-235, 2000Occurrence and distribution of Rhabditis axei (Rhabditida; Rhabditidae) in African giant snails in southwestern Nigeria A. B., ODAIBO, A. J., DEHINBO, L. K., OLOFINTOYE1, O. A., FALODE Department of Zoology, University of Ibadan, Ibadan-Nigeria; 1Deparment of Zoology, Ado-Ekiti University, Ado-Ekiti-Nigeria, E-mail: firstname.lastname@example.org
African giant snails (Archachatina marginata ovum Pfef-fer, 1858; A. marginata saturalis Philippi, 1849 and Achatina achatina Linne, 1758) were examined for the occur-rence of Rhabditis axei Cobbold, 1884.Differences in parasite intensity between size groups of snails were highly significant (p < 0.05) for the 3 species compared. The mean egg and larval output per gram of faeces was higher in larger snails. The mean intensity of the nematode eggs excreted was higher (p < 0.05 ) than the mean of larval output for the 3 species of snails. The di-stribution of R. axei within the snail hosts revealed site preferences. They are mostly (88 %) located in the rectum of the snails.
HELMINTHOLOGIA, 37, 4:2-235, 2000Research note
Amino acid contents in Contracaecum himeu and C. rudolphii (Nematoda: Anisakidae), parasites of cormorants
S. Kracmar , V. Barus1, F. Tenora Mendel University of Agriculture and Forestry Brno, Zemědělská 1, 613 00 Brno, Czech Republic, E-mail: email@example.com; 1Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Kvetna 8, 603 65 Brno, Czech Republic
In mature specimens of two anisakid nematodes (Contracaecum himeu and C. rudolphii) from cormorants from Japan and Europe, 17 amino acids were determined. The contents of these amino acids were very similar in both species, and statistically distinguishable (P 0.05) contents were found for only serine and methionine. Males and fe-males of C. rudolphii had higher (P 0.05) contents of ar-ginine and serine than those of C. himeu, respectively. There was a sexual difference in the content of some ami-no acids: in C. himeu, the contents of alanine, valine, me-thionine (P 0.05), arginine and cystine (P 0.01) were higher in males, whereas in C. rudolphii, those of tyrosine, lysine (P 0.05), alanine, valine, phenylalanine, valine, and arginine (P 0.01) were higher in females. The similarity of amino acid contents in the two nematode species supports their close relationship in taxonomy.