Volume 47 (2010): Edizione 3 (September 2010)

The family Paratylenchidae (Paratylenchus, Gracilacus) belonging to the suborder Criconematina Siddiqi, 1980 including several others families: Criconematidae Taylor, 1936, Hemicycliophoridae Skarbilovich, 1959, Shaeronematidae Raski & Sher, 1952 and Tylenchulidae Skarbilovich, 1947. Members of these families are parasites of higher plants with a higher abundance in perennial cultural plants. Generally we can consider members of the suborder Criconematina as numerous, adaptable, more or less specialized plant parasitic nematodes occurring worldwide. The main common features of specimens of this suborder are relatively long and robust stylet and small body size. This combination enabled them to inhabit also very poor sites in considerable numbers where other nematodes have no chance. A stylet of Paratylenchus nematodes is from 10 to 40 μm of length, the Gracilacus nematodes from 40 to 120 μm of length. The nematodes of the genus Paratylenchus with shorter stylet attack and damaged the cuticular cells of host roots, however, the nematodes of the genus Gracilacus with the longer stylet are able to damage a deeper level of plant roots. Presented review should serve as a list and an outline of what was by some members of the genera Paratylenchus and Gracilacus previously published in connection with trees and grassland.

Molecular comparative analysis of eggs of four liver and stomach flukes of cervids and domestic ruminants, Fasciola hepatica, Fascioloides magna, Dicrocoelium dendriticum and Paramphistomum cervi, was performed using a new methodological approach for eggshell disintegration. Eggs of all species were crushed mechanically by the Teflon method (PTFE) without use of chemical reagents and an efficient disruption of eggshell was checked microscopically. The egg suspension was then subjected to DNA isolation and PCR amplification using species-specific primers that annealed to the internal transcribed spacer 2 (ITS2) region of ribosomal DNA. The size of PCR products of individual species corresponded well to the size of amplicons obtained from adult flukes. The results provided evidence that the Teflon method does not destroy the structure of egg DNA, thus making the procedure broadly applicable during coprological examinations. Molecular markers introduced here are particularly important for blanket screening and differentiation of morphologically hardly distinguishable F. hepatica, F. magna and P. cervi eggs.

The specific humoral immune response of the host (mouse) to the infection with low doses of larvae of encapsulating (Trichinella spiralis, T. britovi) and non-encapsulating (T. pseudospiralis) species was studied. Mice were experimentally infected with 10 muscle larvae of the parasite to simulate natural conditions of the infection in rodents, important reservoirs of trichinellosis. The low infective dose of T. spiralis and T. britovi did not evoke an increased specific IgM response, which is typical for the acute infection. Only T. pseudospiralis induced a higher specific IgM level in the intestinal phase of the infection, till day 30 p.i. The low infective dose of T. spiralis larvae stimulated a specific IgG1 production from day 20 p.i. with a strong increase on day 45 p.i., but T. britovi infection on day 60 p.i. Specific IgG1 antibodies were not detected in T. pseudospiralis infection. The production of IgG2a and IgG2b antibodies was again earlier and more expressive in T. spiralis infection from day 45 p.i., in contrast to T. britovi, where these antibodies were increased on day 60 p.i. Only IgG2b isotype was detected in T. pseudospiralis infection on days 45 and 60 p.i., however in very low values in comparison with encapsulating species.

Results conclude the low infective dose of T. spiralis, T. britovi, and T. pseudospiralis induced a late seroconversion in infected mice. T. spiralis caused earlier and more intensive specific antibody response, from day 45 p.i, when antigens from newborn and muscle larvae were accumulated, on the contrary to T. britovi and T. pseudospiralis, which induced specific antibody response from day 60 p.i.

In this investigation, seventeen Turkish worm lizards, Blanus strauchi, and eighteen slow worms, Anguis fragilis, collected from Turkey, were examined for helminths. Blanus strauchi harbored 2 species of Nematoda: Pharyngodon spinicauda and Aplectana sp. (larvae); Anguis fragilis harbored 5 species of Nematoda:, Rhabdias bufonis, Entomelas entomelas, Oswaldocruzia filiformis, Cosmocerca ornata and Oxysomatium brevicaudatum. Blanus strauchi represents a new host record for Pharyngodon spinicauda and Aplectana sp. Anguis fragilis, represents a new host record for Cosmocerca ornata. Turkey is a new locality record for Pharyngodon spinicauda.

In order to examine the ecological relationships of metazoan parasites and their hosts, 63 specimens of Steindachnerina brevipinna have been collected from April to September 2006, in the rivers Guairacá and Corvo, tributaries of the low Paranapanema River. Five different parasite species have been found (Paranaella sp., Sphicterodiplostomum musculosum, Cosmoxynema vianai, Travnema travnema and Spinoxyuris sp.), with parasite richness from 1 to 4. The dominance index (C > 0.25) was calculated for S. musculosum and aggregation of S. musculosum and Paranaella sp. were reported. There were no associations or covariations between the species of parasites. Values did not show interference of parasite abundance at different gonadal maturity stages. The relative condition factor (Kn) did not show significant values regarding quantitative and qualitative data on parasitism. Statistical tests were significant between the prevalence and the abundance of parasites and the standard length of the hosts, as well as for the parasite abundance in different months and tributaries.

The fine structure of the buccal capsule of the adult female nematode Anguillicoloides crassus (Spirurina) was studied for the first time. Results are based on serial section (longitudinal and transverse) light and transmission electron microscopy. The buccal capsule of A. crassus is a cuticular-lined structure. It can be divided into three main parts: cheilostom, gymnostom and stegostom. The cheilostom is the anterior region of the buccal capsule with the cuticular lining continuous with the body wall cuticle and underlain by epidermal syncytia. The gymnostom is a cuticular region with portions of it very electron dense and underlain by arcade syncytia. A dense circumoral cylinder together with the circumpharyngeal ring represent the prominent characters of the gymnostom. The stegostom is formed by anterior pharyngeal cuticle underlain by muscular radial cells and epithelial marginal cells. The cephalic cuticle of A. crassus makes a direct contact with the pharyngeal cuticle at the base of the circumoral cylinder, within a circumpharyngeal ring containing projections of pharyngeal muscular and marginal cells. The circumoral cylinder, circumpharyngeal ring and pharynx are connected to the body epidermis by junctional complexes. The buccal capsule includes occasionally 3 projections of the pharynx evidently observed in serial cross sections. These ultrastructural characters may provide useful data for comparative, functional as well as evolutionary studies within the Chromadorea.

The spatial and temporal dynamics and composition of a soil free-living nematode community were studied in order to determine the impact of slope orientation on the community on the xeric south- and the mesic north-facing sand-dune slopes.

A significant effect of sampling location on organic matter, total number of free-living nematodes, and trophic diversity was found. Although soil moisture had a significant effect on separate nematode trophic groups and on most of the applied ecological indices, no differences in soil moisture were observed between slopes. Organic matter was found to have a significant effect on the fungivore nematodes. The obtained results indicate that the south-facing slope is more favorable for the observed free-living nematodes than the other sampling sites. Twenty-four of the 77 nematode species that were found in the observed area showed dependence on dune slope orientation. The fungibacteria ratio, Simpson’s dominance index, and basal index were useful tools for determining slope differences.

Taenia saginata, is a cestode with zoonotic potentially. The objective of this work was to evaluate the ovicide activity (type 3 effect) of the fungus, Paecilomyces lilacinus (PL1), on the eggs of Taenia saginata, in vitro. The eggs were inverted in Petri dishes containing PL1, or in Petri dishes without the fungus (control). After 5, 10, or 15 days, we extracted approximately 100 eggs for evaluation and for classifying the ovicide activity. At the end of the 15 days of interaction, a significant difference (p < 0.05) due to the ovicide activity of PL1, was noted in relation to the control group, with a medium percentage (type 3 effect) at 24.6 %. These results show that the fungus, P.lilacinus (PL1), destroyed the eggs of T. saginata, suggesting its biological control potential of the eggs of this cestode.

Echinococcus granulosus, a zoonotic tapeworm with a dog-herbivore life cycle, is known to use ruminants, horses, pigs, etc., as intermediate hosts. Natural infections of hydatid cysts have not been documented in small animals like rabbits in India. This paper records spontaneous intrathoracic, extrapulmonary hydatid cysts of E. granulosus in a cage reared rabbit. The presence of non-invasive unilocular cyst with typical protoscolices containing rostellar hooks favoured the diagnosis of E. granulosus over E. multilocularis, the only other Echinococcus species found in India. The presence of fertile hydatid cyst points to the fact that rabbits can also act as natural intermediate hosts for E. granulosus. The significance of the findings in relation to public health importance is discussed.

A survey has been carried out to study the occurrence and distribution of Paratrichodorus pachydermus nematodes in the Czech Republic in a range of habitats (orchards, forests, vineyards, strawberry and river bank). A total 208 sites were surveyed and 19 sites were found positive for P. pachydermus. This species is a new record for Czech nematofauna.