Molecular variations based on RAPD among oxyurids in Egypt

Pinworms are nuisance parasites of man and animals. In addition to the human pinworm Enterobius vermicularis, Syphacia muris has been reported to infect man. Morphological differences between pinworm species are difficult to determine. Polymerase chain reaction [PCR] based assays including random amplified polymorphic DNA [RAPD] have been used effectively as a complementary approach for fast and simple detection of genomic variability and similarity among parasites. Such information is essential for accurate identification and for finding appropriate experimental models for species under study. The present study seeks to investigate the degree of similarity between the encountered pinworms aiming to find out the closely related species to E. vermicularis to be used as an experimental model. This is evaluated through RAPD-PCR using ten arbitrary primers to differentiate between the encountered pinworm species. The results are statistically evaluated to reveal the significant variations and to specify the degree of similarity and divergence between the encountered species. The pinworms included in this study are: Syphacia obvelata from the house mouse Mus musculus, S. muris from the black house rat Rattus rattus, E. vermicularis from infected children and Aspiculuris tetraptera from the white laboratory rats Rattus norvegicus alba. The degree of similarity between the encountered species was evaluated by PCR-RAPD using the following ten arbitrary primers: OPB-03 [5-CAT CCC CCT G-3], OPB-06 [5- CAT CCC CCT G-3], OPB-19 [5- ACC CCC GAA G-3], OPC-02 [5- GTG AGG CGT C-3], OPC-05 [5- GAT GAC CGC C-3], OPC-14 [5- TGC GTG CTT G-3], OPD-03 [5- GTC GCC GTC A-3], OPD-13 [5- GGG GTG ACG A-3], OPE-07 [5- AGA TGC AGC C-3], and OPE-12 [5- TTA TCG CCC C-3]. PCR-RAPD technique produced common as well as species specific multiband fingerprints with the ten used arbitrary primers for S. obvelata, S. muris, A. tetraptera and E. vermicularis. These variations proved valid for differentiation between the oxyurid species in Egypt. OPC-02, OPC-14 and OPD-3 revealed higher similarity between E. vermicularis and S. muris than with the other pinworm species. Seven of the ten tested arbitrary primers [OPB-03, OPB-06, OPB-19, OPC-05, OPD-13, OPE-07, and OPE-12] revealed that the similarity between A. tetraptera and E. vermicularis is higher than that between E. vermicularis and both Syphacia species. The present study concluded that the primers used in the present study can be used to differentiate between the encountered species and that A. tetraptera and S. muris can be used as experimental models for studying enterobiasis

In-vitro evaluation of antihelminthic activity of Allium sativum against adult Cotylophoron cotylophorum [Paramphistomidae]

Plant-based anti-helminthics have been reported for their safety and eco-friendly properties. They are used as alternatives for toxic chemical drugs. Allium sativum [garlic] has shown antihelminthic action in vitro and in vivo against many helminthes. The present study was designed to evaluate the in vitro antihelminthic activity of A. sativum in comparison with two commonly used antihelminthic drugs; albendazole and niclosamide against the cattle amphistome, Cotylophoron cotylophorum. Live adult C. cotylophorum worms were collected from the rumen and reticulum of slaughtered cattle. Twelve media [natural calf serum, RPMI 1640 in ten formulas and normal saline] were evaluated to choose the most favorable one for incubation of worms during the study. Different concentrations of albendazole, niclosamide and alcoholic extract of A. sativum were tested in vitro against C. cotylophorum. Treated worms were examined after 2, 4, 8, 12 and 24 hours and the mortality rate was calculated in all experiments. The effect of the sub-lethal concentrations of albendazole and A. sativum on the tegument of the worm was evaluated by scanning electron microscopy [SEM]. Albendazole was highly effective against adult C. cotylophorum, where it exhibited dose-dependent lethal activity at different concentrations. Niclosamide was less effective, with high mortality rates recorded at relatively higher concentrations than albendazole. SEM revealed remarkable changes in the tegument and muscles of adult C. cotylophorum treated with a sub-lethal concentration of albendazole [1.5 mg/L] for eight hours. The whole tegument was deformed and papillae were hardly seen as swollen bodies. Numerous blebs and crater-like structures covered the whole tegument. A. sativum alcoholic extract gave high mortality rate at a relatively low concentration. SEM of adult worms treated with a sub-lethal concentration of A. sativum alcoholic extract [1.0 mg/L] revealed moderate changes in the tegument and a more severe effect on the muscle integrity. The mouth appeared flaccid and slightly retracted and the tegument surrounding it appeared feebly damaged and corrugated. The papillae lost their uniform structure. The acetabulum appeared retracted and lost its specific shape. The present study revealed that A. sativum alcoholic extract has an antihelminthic effect against adult C. cotylophorum at low concentrations. Garlic-based antihelminthic product may be used against rumen cattle amphistomes as an alternative for the commonly used chemical drugs

Some ultrastructrual studies on the excretory bladder of the adult cynodiplostomum azimi [trematoda: digenea] in infected rats

Transmission electron microscope was used to reveal the reserve bladder system of the adult Cynodiplostomum azimi in experimentally infected rats. It was shown that this system consisted of a number of lacunae. The lacunar lining appeared as syncytial epithelium containing many nuclei, mitochondria, dense secretory bodies, Golgi complex and bundles of smooth muscles. The outer surface of the excretory epithelium was highly folded and lamellated. These lamellae were continuous with the excretory epithelium. Small lipid droplets were observed within the excretory epithelium, while larger ones were associated with the lamellae. The large lipid droplets were released in the lacunal lumen after the rupture of the lamellae surrounding them

Scanning electron microscopy of the small intestine of rats experimentally infected with cynodiplostomum azimi

Scanning electron micrographs of the proximal intestine of rats infected with C. azimi showed mild villous changes and excessive mucus secretion as early as the first day after infection. On the second day, the regular leak-like pattern of the villi was not seen, the epithelial lining of the mucosa was damaged with large amounts of mucus. Goblet cell openings appeared either empty or filled with secretions. The mucosal damage persisted for three months. Four months after infection, villi regained part of their normal pattern. Their epithelial lining although less damaged, appeared delicate. Villi away from the worm were less affected. Pathological changes at different intervals of infection were discussed in relation to the surface structure of the parasite