Diagnostic potential of Fasciola gigantica-derived 14.5 kDa fatty acid binding protein in the immunodiagnosis of bubaline fascioliasis.

The 14.5 kDa fatty acid binding protein (FABP) was isolated from the crude extract of adult Fasciola gigantica worms. Polyclonal anti-FABP IgG was generated in rabbits immunized with prepared FABP antigen. Sandwich enzyme-linked immunosorbent assay (ELISA) was applied to detect coproantigen in stools and circulating Fasciola antigen (CA) in sera of 126 water buffaloes by using purified and horseradish peroxidase (HRP)-conjugated anti-FABP IgG. Sandwich ELISA sensitivity was 96.97% and 94.95%; while specificity was 94.12% and 82.35% for coproantigen and CA detection, respectively. However, sensitivity and specificity of the Kato-Katz technique was 73.74% and 100%, respectively. The diagnostic efficacy of sandwich ELISA was 96.55% and 93.1% for coproantigen and CA detection, respectively. In contrast, the diagnostic efficacy of the Kato-Katz technique was 77.59%. In conclusion, these results demonstrate that the purified 14.5 kDa FABP provides a more suitable antigen for immunodiagnosis of early and current bubaline fascioliasis by using sandwich ELISA.

Ultrastructural characteristics and histological impacts of Myxobolus naffari (Myxozoa: Myxosporea) infecting Nile labeo Labeo niloticus (Osteichthyes: Cichlidae).

We describe the ultrastructural characteristics and histological impacts of Myxobolus naffari Abdel-Ghaffar et al., 1998, which infects the Nile fish Labeo niloticus. The prevalence of infection was 65%, with the maximum rate occurring during winter and a lower rate during summer. The histological impacts were manifested as a fusion of the gill epithelia, hyperplasia at the ends of the plasmodia, and atrophy of the external surface of the plasmodia. The ultrastructural study revealed that the plasmodial wall was composed of a single unit membrane and bound externally by a thick layer of collagen fibers. The earliest recognizable stage was the disporous pansporoblast. The development of the parasite was asynchronous, with mature and immature spores randomly distributed throughout the plasmodium.

Trichodinid ectoparasites (Ciliophora: Peritrichida) of some River Nile fish, Egypt.

Four species of trichodinid ectoparasites (Ciliophora: Peritrichida) were collected from the gills of the following River Nile fish in Egypt: Hydrocynus forskalii, Mormyrus kannume, Schilbe mystus. These species are: Trichodina heterodentata Duncan, 1977, Trichodina fahaka sp. n., Trichodinella epizootica Raabe, 1950, Tripartiella dactylodentata sp. n. Photomicrographs and morphometric data are presented for each species.

Ultrastructure of a Sarcocystis sp. infecting skinks of the genus Agama.

Macroscopically visible sarcocysts were observed in the skeletal muscles of naturally infected skinks of the genus Agama (infection rate 11.3%). Sarcocysts were described by means of transmission electron microscopy. These cysts measured 0.03-0.25 x 0.38-1.7 mm (mean 0.12 x 1.1 mm). Typical mature cysts were bordered by a primary cyst wall that measured 2.4-5.3 microm (mean 3.9 microm) and was folded into a few nonbranched finger-like protrusions measuring 0.7-1.5 x 1.0-2.5 microm (mean 1.2 x 1.5 microm). These protrusions contained granular elements, but filaments and tubular elements were not observed. A relatively thick, homogeneous tape was observed just underneath the primary cyst wall, measuring 0.5-1.0 microm (mean 0.8 microm) and containing a granulated ground substance in which filaments and tubular elements were not observed. Metrocytes measured 3.1-5.5 x 4.2-7.2 microm (mean 4.0 x 5.8 microm) and merozoites measured 1.2-3.3 x 4.4-8.6microm (mean 2.6 x 7.5 microm). The fine ultrastructural characteristics of both metrocytes and merozoites were similar to those described for many Sarcocystis species and were generally nonspecific.

Endodyogony and cyst formation of Sarcocystis gongyli (Trinci 1911) from the skink Chalcides ocellatus.

The heteroxenous life cycle of S. gongyli comprising both the skink Chalcides ocellatus (intermediate host) and the snake Spalerosophis diadema, herewith the process of cyst formation was followed by means of light and electron microscopy after experimental infection. Following migration of the merozoites to muscle fibres, they changed into globular metrocytes, meanwhile a parasitophorous vacuole enclosing them. As development proceeded the wall of the parasitophorous vacuole is thickened in the form of striated protrusions as well as the metrocytes underwent endodyogony producing large numbers of banana-shaped merozoites in the centre of the cyst. Mature microscopic sarcocyst appeared at 120 days p.i, and these were characterized by presence of stalky leaf-like protrusions in their primary cyst wall. Asexual multiplication of metrocytes occurred through endodyogony in which always the mother metrocyte produced two opposite merozoites.

Light and electron microscopic studies of Myxobolus stomum n. sp. (Myxosporea: Myxobolidae) infecting the blackspotted grunt Plectorhynicus gaterinus (Forsskal, 1775) in the Red Sea, Egypt.

A new myxosporean parasite, Myxobolus stomum n. sp., is described from the oral cavity and lips of the blackspotted grunt Plectorhynicus gaterinus (Forsskal, 1775) in the Red Sea, Egypt. The parasite was observed as tiny aggregates of whitish cysts hardly noticed within the muscles of the oral cavity, especially within the lips. The spores were subspherical and measured 8.5x6.5 microm. Polar capsules were equal, pear-shaped, occupied about half of the spore length and measured 4.4x2.4 microm. Histological evaluation of the infection revealed no significant impact on the host. The ultrastructure of the plasmodial wall and sporogenesis of the present species followed the usual pattern valid for most studied myxosporean species.