Ligulosis in two cyprinid hosts: Rutilus rutilus and Gobio gobio
C. ArmeCentre for Applied Entomolgy and Parasitology, Keele University, Staffordshire, ST5 5 BG, United Kingdom
SummaryThe pathology of Ligula-infections in Rutilus rutilus and Gobio gobio differs in several respects. In natural infections of R. rutilus, there is a pronounced host cellular response which can be demonstrated in fry shortly after infection and which becomes more pronounced with fish age. In contrast, no cellular response is ever found in natural infections of G. gobio. It has been proposed that parasites from R. rutilus and G. gobio differ in their ability to stimulate a host response. Transplantation experiments lend support to this view, although it cannot be excluded that host factors may also play a role. There are quali- tative and quantitative differences in splenic and pronephric leucocyte counts, and in spleen weights, between the two hosts.In R. rutilus, infection is invariably accompanied by cytological changes in the gonadotrophs of the pituitary gland, and an inhibition of gonadal development. Thus, the gonads fail to undergo seasonal cycles of development and regression, and they resemble those of immature fish, irrespective of host age. Detailed studies have not been undertaken with G. gobio. However, such cytological evidence as is available indicates that, although pituitary gonadotrophs are reduced in apparent number in infected fish, gametogenesis proceeds further in parasitised G. gobio than in R. rutilus. It is suggested that these differences might indicate that Ligula from R. rutilus and G. gobio are different strains or species. Although comparison of isoelectric focusing gels of parasite extracts supports this view, with seven of 43 identifiable bands differing in worms from the two hosts, evidence from enzyme analysis does not.
HELMINTHOLOGIA, 34, 4: 197 - 205, 1997
Albendazole treatment and liver fibrosis in mice infected with Mesocestoides vogae (syn. corti) tetrathyridia (Cestoda): a preliminary study
G. Hrckova, S. Velebny, B. S. Dezfuli*Parasitological Institute SAS, Hlinkova 3, 040 01 Kosice, Slovak Republic; *Dipartimento di Biologia, Universita di Ferrara, Via L. Borsari, 46 - 44100 Ferrara, Italy
SUMMARYThe efficacy of 10 doses of albendazole (ABZ) administered to mice during different periods post-infection (p. i.) was calculated and assessed in the light of the process of liver fibrogenesis. The highest efficacy of subcurative doses of ABZ was achieved after treatment between days 3—12 p. i. When the drug was given to mice after the initiation of liver fibrosis and when collagen was evident around the tetrathyridia, the efficacy of drug in the livers decreased. The late treatment (days 23—32 p. i.) resulted in a further decline in the larvicidal effect of ABZ on liver tetrathyridia. In contrast, in the peritoneal cavity the efficacy of ABZ increased with time p. i., in spite of increasing numbers of tetrathyridia. The mean number of damaged/resorbing larvae in either treated group correlated with the efficacy. Thus, after early treatment there was slightly decreased collagen deposition in the liver paraenchyma in comparison with the control group. These data indicate that at this drug regime the most important factor to have impact on efficacy was the stage of fibrous encapsulation around the tetrathyridia. The fibrous capsules serve as a mechanical barrier to further migration and damage by the parasites, while, at the same time, they limit the availability of active ABZ-SO to the encapsulated tetrathyridia.
HELMINTHOLOGIA, 34, 4: 207 - 213, 1997
On the variability of Brachylecithum strigosum (Looss, 1899) (Trematoda, Dicrocoeliidae) in Cuculus canorus L. (Cuculiformes) in Slovakia
J. K. Macko, J. C. Casanova*, M. SpakulováParasitological Institute SAS Hlinkova 3, 040 01 Kosice, Slovak Republic; *Departmento de Microbiologia y Parasitologia sanitarias, Facultad de Farmacia, Universidad de Barcelona, Avda Diagonal s/n, 08028 Barcelona, Spain
SummaryOver 200 dicrocoeliids Brachylecithum strigosum (Looss, 1899) were obtained from livers of common Eurasian cuckoos, Cuculus canorus L. in eastern Slovakia. Morphological analysis of 96 worms coming from 8 hosts (8 organophenotes) revealed a remarkably high variation either within digenean intrapopulation communities coming from various host individuals and among them. Generally, B. strigosum specimens were characterised by elongate, slender body 2.80—6.35 mm long and 0.14— 0.49 mm wide. Diameters of both oral and ventral suckers were of about 0.2 mm, their ratio 1 : 0.83—1.22 (1.01). Testes and ovary were tandem, ovary often slightly larger. Small eggs measured 0.037—0.048 mm in length and 0.022—0.030 mm in width. The discussion analyses the systematic position of B. strigosum relative to the "oldest" taxa in the genus Brachylecithum.
HELMINTHOLOGIA, 34, 4: 215 - 219, 1997
Philonema percichthydis sp. n. (Nematoda: P h i l o m e t r i d a e) from the Patagonian smallmouth perch Percichthys trucha (Pisces) from Argentina
F. MORAVEC1, S. URAWA2, C. O. CORIA31Institute of Parasitology, Academy of Sciences of the Czech Republic, Branisovska 31, 370 05 Ceske Budejovice, Czech Republic; 2Research Division, National Conservation Center, Fisheries Agency of Japan, 2—2 Nakanoshima, Toyohira-ku, Sapporo 062, Japan; 3Centro de Ecología Aplicada del Neuquén, CC 7, 8371 Junín de los Andes, Neuquén, Argentina
SummaryA new philometrid species, Philonema percichthydis sp. n., is described fro two gravid female nematodes collected from the abdominal cavity of the freshwater fish Percichthys trucha (P e r c i c h t h y i d a e, Perciformes) from Lake Aluminé, Patagonia, Argentina. From all hitherto known species of Philonema it differs in having a markedly long oesophagus (3.81—4.34 mm), distinctly larger larvae (body length 0.600—0.840 mm) in the uterus, in the presence of a functional anus and in the host type and the geographical distribution. Its cephalic and caudal structures were studied by scanning electron mic- roscopy (SEM). P. percichthydis is the first species of this genus recorded from a perciform fish and the first Philonema species described from South America.
HELMINTHOLOGIA, 34, 4: 221 - 227, 1997
Helminth fauna of Porichthys porosissimus (Pisces: Batrachoidiformes) in the estuary of Bahia Blanca Argentina
R. D. Tanzola, S. E. Guagliardo, S. M. Brizzola, M. V. Arias**Cátedra de Parasitologia, Departamento de Biologia, Bioquimica y Farmacia, Universidad Nacional del Sur 8000 Bahia Blanca, Argentina, e-mail: rtanzola@criba.edu.ar
SummaryThe specific diversity in parasitic helminths of the Atlantic midshipman, Porichthys porosissimus, is analyzed. The relationships between size and both specific richness and abundance of helminths were studied through non parametric tests. So were trophic preferences regarding sex and size. The dispersion type of the parasites in the hosts' populations was determined. Thirteen species of helminths: 4 cestodes Grillotia erinaceus (van Beneden, 1858), Nybelinia lingualis (Cuvier, 1817), Scolex pleuronectis (= S. polymorphus) Müller, 1788 types 1 and 2, 2 trematodes Lecithochirium parvum (Manter, 1947) and Dollfustrema sp., 2 acanthocephalans Corynosoma hamanni (Linstow, 1892) and C. australe Johnston, 1937 and 5 nematodes Ascarophis marina (Szidat, 1961), Contracaecum sp., Pseudoterranova sp., Cucullanus sp. and a Rhabdochonid are cited for the first time in P. porosissimus from the south-western Atlantic. All of the component species (prevalence > 10 %) are distributed in an overdispersed manner. Because of their high parasite prevalence, intensity and abundance, G. erinaceus and S. pleuronectis types 1 and 2, are considered dominant in the system. The community of intestinal helminths comprises the tetraphyllidean larvae Scolex pleuronectis and adults Lecithochirium parvum. There is no statistically significative correlation between richness in species and host's size. A slight tendency to increase the total parasite burden with size was observed, starting from the one at which reproductive maturity is reached. The members of the system are not significantly associated. The majority of the species were found in the larval stage, indicating an intermediate trophic position of the fish in the predator-prey system.
HELMINTHOLOGIA, 34, 4: 229 - 234, 1997
Effect of anaerobic stabilization of sewage sludges on the survival of Ascaris suum under laboratory conditions
P. Plachy, I. Placha*, P. JurisParasitological Institute SAS, Hlinkova 3, 040 01 Kosice, *Research Institute of Experimental Veterinary Medicine, Hlinkova 1/A, 040 01 Košice, Slovak Republic
SummarySurvival of Ascaris suum eggs was studied during a laboratory anaerobic stabilization of sewage sludges at a mesophilic and a thermophilic temperatural range. The effect of a 20- and a 30-day sludge hydraulic retention time (HRT) was also followed up with mesophilic stabilization. Mesophilic aerobic stabilization (36°C) with the 20- day HRT showed the mean of 76.8 % and with the 30- day HRT 76.2 % of viable eggs, which is statistically not an important difference (P<0.01). The mean of 94 % of viable eggs were detected in control after 30 days. Ana- lysis of the effect physico-chemical parameters of stabili- zation on the survival of eggs showed no dependence of the percentage of viable eggs in fermentors with the 20- day HRT on pH and in fermentors with the 30-day HRT on pH and concentration of volatile fatty acids.Aerobic thermophilic stabilization (at 54°C) reduced the viable nonembryonated eggs Ascaris suum from 82.4 to 9 % in 10 min. After 10 min of stabilization all eggs were eliminated.
HELMINTHOLOGIA, 34, 4: 235 - 236, 1997
HELMINTHOLOGIA, 34, 4: 237 - 239, 1997
Research note
Sorex unguiculatus Dobson, 1890 (Insectivora) - intermediate host of Echinococcus multilocularis Leuckart, 1863 in Japan
F. Tenora1, 2, S. Ganzorig2, K. Takahashi3, M. Kamiya21Department of Zoology, Mendel University of Agriculture and Forestry, 613 00 Brno, Czech Republic, 2Laboratory of Parasitology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060, Japan, 3Hokkaido Institute of Public Health, Sapporo 060, Japan
SummaryThe metacestode of Echinococcus multilocularis, host Sorex unguiculatus, Hokkaido, Japan is fully described in detail for the first time. The strain of this metacestode from Insectivora is striking by different from other strains of E. multilocularis in the number of rostellar hooks.
HELMINTHOLOGIA, 34, 4: 241 - 243, 1997