Rhabdias bufonis (Rhabdiasidae) from the lung of the African common toad, Amietophrynus regularis (Bufonidae) in Egypt: new data on the basis of light and scanning electron microscopic study.

BACKGROUND AND AIMS: Rhabdias sp. (Rhabdiasidae) is a nematode parasite of family Rhabdiasidae infecting the lung of amphibians. The present study provides new morphological details for Rhabdias bufonis isolated from the lungs of the African common toad, Amietophrynus regularis based on observations of light and scanning electron microscopy (SEM). METHODS: Forty specimens were collected from its natural habitat: the damp, moist fields and gardens at Giza governorate, Egypt. Worms were isolated from the lungs, fixed and then preserved. They were examined using light and SEM with further line drawings. RESULTS: Fourteen specimens (35%) were found to harbor Rhabdias with an intensity of three to five worms per host. Bodies of the gravid females were elongated, slender, measured 3.22-9.86 (5.64 ± 0.03) long and 0.09-0.48 (0.23 ± 0.02) wide at mid-length. Buccal capsule was with cylindrical lumen and sclerotized walls. Ovaries were almost straight. The uteri were located anterior and posterior to the vulva. Uterus were filled with a large number of eggs (17-42). Eggs were oval in shape and some of them were with fully developed larvae inside. The tail was comparatively short, gradually tapered. SEM showed that worms possessed an oval anterior end with a simple, slit like oral opening. The lipless edges of the mouth opening were bordered with tiny cuticular elevations, radiated outwards. Two pairs of submedian cephalic papillae were observed around the oral opening as well as two amphids. CONCLUSION: The current study presents new morphological details for R. bufonis isolated from the African common toad. Also, the morphology of the slit-like mouth opening, the two pairs of cephalic papillae, two amphids and the three pairs of cuticular elevations supporting the area around mouth opening were investigated.

Morphological re-description and new geographical records for three digenean parasites infecting African sharptooth catfish Clarias gariepinus (Pisces: Clariidae) in Egypt.

Sixty specimens of African sharptooth catfish Clarias gariepinus (Clariidae) were collected during the period of March 2014-February 2015 from boat landing sites and fishermen of the River Nile at Beni Suef Governorate, Egypt, and examined for the presence of digenean parasites. The morphology of these parasites was studied by using light microscopy to describe morphological and morphometrically measurements for different body parts. Three digenean species belonging to three different genera were collected from various organs within the examined fish species. A certain degree of site specificity was also observed, with Thaparotrema botswanensis being found only in the gall bladder of C. gariepinus, while both Pseudoholorchis clarii and Glossidium pedatum were found only in the intestine and thus seem to occupy a certain niche within their host. This study represent as the first record of T. botswanensis and G. pedatum from C. gariepinus, as well as the first report of the genera from the River Nile in Egypt. In addition, re-description of P. clarii clarifies measurements for some body parts.

Immunomodulatory effect of diethylcarbamazine citrate plus filarial excretory-secretory product on rat hepatocarcinogenesis.

Diethylcarbamazine citrate (DEC) had a significance in anti-filarial chemotherapy, while excretory-secretory product (ES) is released from adult filarial females. The target of the current study was to examine the immunomodulatory effect of DEC, Setaria equina ES or a combination of them on rat hepatocellular carcinoma (HCC) induced by diethylnitrosamine (DEN). In vitro effect of combined DEC and ES or ES alone on lipopolysaccharide (LPS)-stimulated rat peripheral blood mononuclear cells (PBMCs) was tested through IFN-γ assay in culture supernatants. In addition, single or repeated doses of DEC, ES or DEC+ES have been applied in white albino rats to test the effect on HCC. Levels of IFN-γ and anti-ES IgG antibodies in rat serum were assayed using ELISA. Hemolytic complement activity (CH50) was determined in serum while the concentration of nitric oxide (NO) was assayed in liver tissue. The infiltration of NK cells as well as the expression of MHC Iproliferating cell nuclear antigen (PCNA), inducible NO synthase (iNOS), Bcl2 and p53 were determined using immunohistochemistry. There was a dose-dependent increase in IFN-γ after in vitro exposure to DEC+ES. Repeated ES doses increased NO concentration (p<0.05) and expression of iNOS but reduced CH50 (p<0.001), while repeated DEC+ES doses could increase anti-ES IgG (p<0.01), IFN-γ level (p<0.05) and NK cell infiltration. The same treatments could also reduce the expression of MHC I expression, PCNA, Bcl2 and p53. This study has shown immunomodulatory and protective effects of DEC+ES repeated doses on rat HCC.

Effect of diethylcarbamazine citrate and Setaria equina excretory-secretory material on rat hepatocellular carcinoma.

Diethylcarbamazine citrate (DEC) has been known for its efficacy to eradicate bancroftian filariasis in Egypt and other countries in the world. One of the known effects was to decrease the level of circulating filarial antigen in the patient's serum. The target of this study was to examine the effect of DEC, excretory-secretory (ES) material from the filarial parasite Setaria equina or a combination of both on the status of oxidative stress and pathogenesis of rat hepatocellular carcinoma (HCC) induced by diethylnitrosamine and 2-acetylaminofluorene. This could be tested in vitro using nitroblue tetrazolium reduction test for measuring the level of superoxide anion (O2(•-)) released from rat peritoneal macrophages. For in vivo test, a single dose before induction of carcinogenesis or continually repeated doses with DEC, ES or DEC + ES was used. Exposure of macrophages to ES could lead to a significant decrease (p < 0.01) in O2(•-) release, while DEC (200 µM) could modulate such effect with significant increase (p < 0.05). Pathogenesis of liver cancer and treatment were evaluated using histological investigation, level of antioxidant and liver function enzymes. Repeated ES doses could increase the activity of antioxidant enzymes, especially the catalase enzyme and show a protective effect on liver architecture. DEC could modulate the later effects when combined with ES. No significant effect on the liver function enzymes after treatment was observed. Nuclear factor κB was found to be localized only in the cytoplasm after single and repeated treatments with ES. This study could indicate the effect of S. equina ES as antioxidant against rat HCC, while DEC could modulate such effect when combined with it.

Acanthostomum spiniceps (Digenea: Cryptogonimidae: Acanthostominae), a parasite of the African snook Lates niloticus (Perciformes: Latidae). A light and scanning electron microscopic study.

The morphology of the adult stage of Acanthostomum spiniceps recovered from the African snook, Lates niloticus (Perciformes: Latidae) of the river Nile, Egypt was studied with both light and scanning electron microscopy.The most important morphological features differentiating this species are the number of circumoral spines, body shape, ratio of body length to width, sucker sizes, and the presence or absence of spines on the ventral sucker. Sixteen out of forty fish (40%) was found to be naturally infected with this digenetic trematode belonging to family: Acanthostominae. The infection was recorded in the intestinal wall of the host fish. Body was elongate, 1.203-2.074 mm long, maximum width 0.311-0.534 mm. Oral sucker was terminal, funnel-shaped, 0.201-0.353 mm long and 0.245-0.310 mm wide. Simple peribuccal spines 0.042-0.066 mm long. Ventral sucker was circular, 0.110-0.140 mm long, 0.120-0.204 mm wide, situated approximately at 1/3 of body length. Ratio of oral and ventral suckers was 1: 0.5. Testes tandem or slightly diagonal, located near posterior end of body being of irregular rounded shape. Size of anterior testis was 0.130-0.220 mm long, 0.314-0.358 mm wide, that of posterior testis was 0.180-0.274 mm long, 0.390-0.327 mm wide. Ovary transversely oval, smaller than testes, measured 0.102-0.166 mm long, 0.100-0.164 mm wide, situated just anterior to anterior testis. By comparison with some of the previously described species of this genus, the present one showed all morphological characters and the most morphologically similar species was A. spiniceps.

Life cycle of Sarcocystis camelicanis infecting the camel (Camelus dromedarius) and the dog (Canis familiaris), light and electron microscopic study.

In the present study, the heteroxeneous life cycle of Sarcocystis sp. infecting camels were studied. A total of 180 slaughtered camels collected from different localities in Egypt were investigated for sarcocysts. Only 116 animals were found to be infected (the infection rate was 64%). Muscle samples of esophagus, diaphragm, tongue, skeletal, and heart muscles were examined. Exclusively, microscopic sarcocysts were detected in all examined organs. The infection rates of the esophagus, diaphragm, tongue, skeletal, and heart muscles were 60%, 50%, 40%, 40%, and 10%, respectively. By means of transmission electron microscopy, details of the ultrastructure of the sarcocysts were studied. The specific architecture and ornaments of the cyst wall, its protrusions, and the cyst interior were recorded. Unique features of protrusions of the primary cyst wall, the knob-like structures, arise around each protrusion. Experimental infection of carnivores by feeding heavily infected camel muscles revealed that the dog, Canis familiaris, is the only final host of the present Sarcocystis species. Gamogony, sporogonic stages, and characteristics of sporulated oocysts were also investigated.