الفهرس | Only 14 pages are availabe for public view |
Abstract Fish parasites are of economic and health importance where they cause serious problems in commercial fish farms and it can be transferred to human and animals. Fish borne parasitic infections are induced by eating raw or improperly cooked or pickled fish. Capillaria species are nematodes of serious fish diseases which may be transferred to human. Capillaria sp. are nematodes of many different species infecting a wide range of vertebrate hosts, some infect human hosts causing serious parasitic diseases. Capillariasis is a severe disease that may lead to death unless patients are treated. Although chemical drugs have been used for treatment against such parasitic nematodes, but, these drugs have some side effects. Recently, medicinal plants have been used as available replacement for chemical drugs which may be toxic to host or harmful to its surrounding environment. Aim of study:- The present study aims to throughout the light on fish capillarides in Menoufia and Kalyobia Governorates to add to the available information on the identity of this species. 1) Collection and description of the most common Capillaria sp. infecting Bagrus docmac and B. bayad fishes collected from Menoufia and Kalyobia Governorates. 2) In vitro evaluation of the anthelminthic activity of albendazole and three medicinal plants (Allium sativum, Lupinus termis, and Cucurbita pepo) on Capillaria sp. 3) In vitro evaluation of the effect of albendazole in comparison with that of A. sativum on the fine structure of Capillaria sp. ultrastructure using scanning and transmission electron microscopy. 4) Characterization of Capillaria sp. using RAPD-PCR technique. Only female specimens were collected. Summary and Conclusion 89 The findings can be summarized as follow:- 1. Morphological structure of collected Capillaria sp.: Specimens appeared small, slender, white in color and measuring 3-7 mm in length and 0.03-0.08 mm in width. Oral opening is terminal leading to oesophagus which consists of two parts: muscular part and stichosome which is the glandular part and formed of a single row of glandular cells (23-36 glandular cells have a big central nuclei). Uterus is present in the second third of the worm body, filled with eggs and ends with the vulva. Ovary is located in the last third of the worm body. The intestine ends at the posterior part of the body with a terminal anal pore. 2. Fine structure of collected Capillaria sp.: A. Scanning electron microscopy:- Scanning electron micrographs (SEM) show that the oral opening is anteriorly oriented and surrounded by three distinct lips (one dorso-lateral and two ventro-lateral). Cephalic papillae are indistinct. Characteristic transversely striated cuticular annulations appear just behind the mouth opening and extend posteriorly till the end of the body. Two distinct lateral bacillary bands extend along the whole body length. The openings of the bacillary band cells appear as round pores containing semi-granular material. The vulva is simple, and located at the second third of the body . The anus is terminal. Many small papillary structures, possibly sensory in function are found in the terminal end arranged in a circular pattern around the anus. B. Transmission electron microscopy:- Cross section of the worm body showed three basic layers : cuticle, hypodermis and muscle layer. Summary and Conclusion 90 1. Cuticle:- Cuticle consists of four layers. It is covered with an outermost triplelayered epicuticle consists of two electron dense layers enclosing an electron opaque one. The outer cortical layer is an electron dense layer with fibrous nature. Fibrillar layer is an electron opaque composed of circularly arranged myofibrils followed by basal layer. The basal layer is differentiated into two layers; an outer thick electron opaque layer which encloses electron lucent area and an inner thin electron opaque layer with circularly arranged myofibrils. Cuticle layer followed by hypodermis: It contains numerous mitochondria, round electron lucent vacuoles. Hypodermis followed internally by muscle layer, which lies against the inner surface of the hypodermis. The bundles of longitudinally arranged muscle fibers are separated by thin cytoplasmic septa. The contractile part is formed of thick and thin myofilaments and encloses mitochondria and dense ovoid structures. The bacillary band as it seen in the present Capillaria sp. is a modified hypodermal chord composed of bacillary band cells originating in an enlarged hypodermal base. Such structures penetrate the cuticle layers and terminate apically in a plug of electron dense material. The translucent plug is located above the flask-shaped glandular (pore chamber). Numerous fine fibrils are resolved in the pore chamber presenting lamellar apparatus together with some electron opaque droplets. Each lamellar apparatus is ensheathed by a thin layer of cytoplasm bounded by plasma membrane, the bacillary sheath. A thick cuticular layer continuous with that covering the body, covers the lamellar apparatus which is underlined by a plasma membrane. The nuclei are situated near the basal part of the cell, each contains a single large nucleolus with large nucleolar mass. Summary and Conclusion 91 2. Digestive system:- The mouth leads to the oesophagus. It is a strongly muscular organ lined with a thick cuticular lining. The oesophagus consists of two distinct parts, the anterior muscular part lined with a thick cuticular lining and the posterior glandular part consists of a single row of large gland cells, the stichocytes. The intestine lies free in the pseudocoelom. The intestinal wall is formed of single layered epithelial cells, laying on a basal lamina. The epithelial cells contain electron dense granular cytoplasm containing elements of endoplasmic reticulum, numerous mitochondria and large nuclei. The intestinal microvilli are numerous, long, electron dense and reduce the lumen size. 3. Female genital system:- The wall of the ovary is composed of thin monolayered endothelium bound by a thin basal lamina. The ovary is filled with ovoid oogonia. The cytoplasm has a heterogeneous appearance and contains mitochondria, electron lucent vesicles and electron dense inclusion bodies. The central rachies are slightly apparent between the oogonia. 3. In vitro maintenance of Capillaria sp: Five different media were used for maintaining Capillaria sp. in vitro, RPMI 1640 (Formula I), RPMI 1640 (Formula II), RPMI 1640 (Formula III), Hanksٔ saline, Natural calf serum in optimum conditions, 20 °C and pH 7. Natural calf serum was the best medium for maintenance of Capillaria sp. as observed by high activity and low mortality rate in the previous conditions for 24 hours exposure time. This media and conditions were appropriate for in vitro screening of anthelminthic and medicinal plants against Capillaria sp. |