Kareem Morsy

Ultrastructure and host parasite relationships of Kudoa pagrusi (Myxozoa) infecting the heart muscles of sea bream Pagrus pagrus (L.) from the Red Sea

The present study is a part of a continuous investigation of myxosporean parasites-infecting fish of the Red Sea using light and electron microscopy. Out of 120, 80 (67%) Pagrus pagrus fish were found to be naturally infected with Kudoa pagrusi. The infection was intensive and appeared as clusters of ovoid to ellipsoidal plasmodia being restricted to the cardiac muscles. Histological studies elaborated tissue distortion at the sites of infection and the adjacent layers. The development of the plasmodia reduced the functional area of the heart muscle. Ultrastructural analysis showed that the plasmodia were surrounded by single-unit membrane with numerous projections and pinocytotic channels extended toward the host cell. The generative cells and the different developmental stages were arranged at the periphery of the plasmodia while immature and mature spores were centrally arranged. The present study showed the main criteria of this genus: the spores possess four polar capsules with four shell valves.

First record of anisakid juveniles (Nematoda) in the European seabass Dicentrarchus labrax (family: Moronidae), and their role as bio-indicators of heavy metal pollution

This study assessed the anisakid nematode distribution pattern in the fish collected from coasts of Mediterranean Sea, Egypt, during the period September 2010–April 2011. Two hundred thirty out of 300 (76.7%) Dicentrarchus labrax (European seabass) marine fishes belonging to family Moronidae were dissected and found to be infected with larva three nematodes. The larvae had been studied by light and scanning electron microscopy. The present work represents the first record of the presence of the parasite in this fish in the Mediterranean Sea. The concentrations of some heavy metals (Pb, Zn, Fe, Cd, Cu, Mn, Ni) in parasites as well as in tissues of fish were measured. The presented results showed that the nematode parasites are able to accumulate heavy metals in their tissues and in some cases that they are able to accumulate large amounts of heavy metals in a higher amount than host tissues. This demonstrated their sustainability as bioindicators of environmental pollution by removing heavy metals and help in the survival of fish.

Prevalence pattern and biology of Sarcocystis capracanis infection in the Egyptian goats: A light and ultrastructural study

Cysts of Sarcocystis capracanis obtained from infected goats were examined to clarify the effect of the parasite on the host. Muscle tissues from fresh oesophagus, tongue, diaphragm and skeletal muscles of 680 goats were slaughtered in the main abattoir of Cairo, Egypt and they were examined microscopically for Sarcocystis infection for the first time in Egypt. 540 out of 680 (79.4%) of examined goats were found to be infected with Sarcocystis sp. The infection was recorded firstly by light microscopy as spindle shaped cysts embedded in the muscle tissues. The validity of this species as S. capracanis was confirmed by means of ultrastructural characteristics of the primary cyst wall which revealed the presence of thick-radially striated wall with finger like projections, underlined by a thick layer of ground substance enclosing the developing metrocytes and merozoites that usually contain nearly all the structures of the apical complex and fill the interior cavity of the cyst. The cyst cavity is divided by many septa extending from the ground substance and producing large number of chambers. An experimental infection using the highly infected muscles was carried out to determine the final host, which is dog. Smears of intestinal epithelium were taken to examine the endogenous stages (gamogony and sporogony) by means of light microscopy. These stages were mainly observed as to infect the lamina propria of the posterior third of the small intestine. Gamogony and zygote formation (fertilization) occurred 2-8 days post infection, while sporulation took place within the final host 13-15 days and sporocysts were passed within faeces of the infected puppies at that time. The prepatent period of S. capracanis was 12-15 days, while the patent period was extended to 37 days. In goats, infection with S. capracanis led to the loss of weight, anaemia, abortion and even death in cases of heavy infection. While bleeding, watery faeces filled with mucous on 5th and 8th day p.i. as well as intestinal lesions are the pathogenic effects occurred in puppies after experimental infection.

Developmental stages of Hepatozoon hemprichii sp. nov. infecting the skink Scincus hemprichii and the tick Hyalomma impeltatum from Saudi Arabia.

abstract:  The life cycle of Hepatozoon hemprichi n. sp. is described; the vertebrate host is Scincus hemprichii and it is vectored by Hyalomma impeltatum. Erythrocytic stages of 18 ± 1.8 × 4 ± 0.8 µm developed in the hemocoel of ticks to sporozoites within 16–18 days. Schizogony occurred in the liver parenchyma and the endothelial cells of blood capillaries in lung and spleen. Mature schizonts measuring 27 ± 3.11 × 20.13 ± 3.0 µm produced 28 merozoites (on average). The merozoites were 13 ± 1.21 × 1.21 ± 0.72 µm with nuclei 5 ± 0.65 × 2.1 ± 0.51 µm. Syzygy and differentiation of gamonts took place in ticks hemocoel up to the third day post-infection (PI). The microgamont (16 ± 0.31 × 18 ± 0.42 µm) produced 4, uniflagellated microgametes at 4–5 days PI. The microgamete measured 15.2 ± 0.31 µm while the flagellum was always at least 26 µm. The macrogamete was very large in size (31 ± 3.11 µm) with a central nucleus. After fertilization, (5–6 days PI) zygotes developed into oocysts (55 ± 3.41 × 52 ± 4.11 µm) in which repeated mitotic divisions with centripetal invaginations occurred; each contained 18 banana-shaped sporozoites, 13.61 ± 0.8 × 1.2 ± 0.31 µm in size. Experimental transmission was successfully carried out by oral administration or by intra-peritoneal inoculation of the infective stages (sporozoites) to uninfected skinks and led to the appearance of blood stages after 5 wk and 4 wk, respectively.

Morphological re-description of Electrotaenia malapteruri (Cestoda: Proteocephalidae) and Dujardinnascaris malapteruri (Nematoda: Heterocheilidae) infecting the Electric catfish Malapterurus electricus and heavy metal accumulation in host and parasites in relation to water and sediment analysis in Lake Manzala, North Delta, Egypt

Parasites are one of the most serious limiting factors in aquaculture. The Electric catfish Malapterurus electricus was subjected to study the prevalence and mean intensity of parasitic infections throughout the whole year of 2015. Heavy metals accumulation in host fish and parasites were determined in relation to water quality and sediments of two different sites of Lake Manzala (Manzala and Bahr El-Baqar), Egypt. A total of 100 specimens of Electric catfish were collected and examined for the presence of helminth parasites. Two parasite species were recovered and morphologically identified. These were cestoda Electrotaenia malapteruri and nematode Dujardinnascaris malapteruri. Heavy metal analysis in water and sediments showed that measured heavy metals in Bahr El-Baqar were found in risky levels higher than permissible limits and Manzala site. Sediments were found to contain a higher level of metals than water samples. Heavy metals accumulation in recovered parasites and their host were also determined and showed significantly higher concentrations in parasites compared to their host tissues. According to bioconcentration factors, E. malapteruri showed that highest accumulation rate for all recorded elements up to 302. Essential elements like Cu and Fe were found in significantly higher concentrations in D. malapteruri, whereas E. malapteruri accumulated elements Cd, Pb, Ni, Mn, Zn and Ca to a significantly higher degree. Accordingly, the ratios (C[D. malapteruri]/C[E. malapteruri]) for most essential elements were higher than 0.5. Therefore, fish cestodes can be regarded as useful bio-indicators more than nematodes when evaluating the environmental pollution of aquatic ecosystems by heavy metals.

Ultrastructural characterization of Pleistophora macrozoarcidis Nigerelli 1946 (Microsporidia) infecting the ocean pout Macrozoarces americanus (Perciformes, Zoarcidae) from the gulf of Maine, MA, USA.

Pleistophora macrozoarcidis a microsporidian parasite infecting the muscle tissue of the ocean pout Macrozoarces americanus collected from the Gulf of Maine of the Atlantic Ocean, MA, USA, was morphologically described on the basis of ultrastructural features. Infection was detected as opaque white or rusty brown lesions scattered throughout the musculature of the fish mainly in the region anterior to anus. Transmission electron microscopy showed that in individual parasitized muscle cells, the infection progresses within parasite formed vesicles which are in direct contact with muscle cell elements. The earliest observed parasitic stages are the globular multinucleated proliferative cells or plasmodia limited by a highly tortuous plasmalemma with intervesicular finger-like digitations projecting into the parasite cytoplasm. These cells divided through the invagination of the plasmalemma and the amorphous coat producing daughter-cells. Fine electron-dense secretion is deposited on the plasmalemma that causes its thickening which is a sign of commencement of the sporogonic phase. This phase is carried out by cytokinesis of the sporonts and results in the formation of sporoblasts and finally spores. Mature spore has a thin electron-dense exospore, a thick electron-lucent endospore, and the plasma membrane which encloses the spore contents. A single nucleus is centrally located with the posterior region containing a posterior vacuole. The majority of spores have 7–13 coils in 1–2 rows, and a small group of spores had about 23 coils forming two rows. Events of polar filament extrusion for penetration of uninfected cells were studied. The polaroplast membranes were expanded and occupy most of the length of the spore. The coils are dislocated from the sides of the spore to throughout the entire sporoplasm. The polar filament everts and extrudes through the polar cap with a sufficient force to pierce adjacent sporophorous vesicle walls. After eversion, the polar filament is referred to as a polar tubule, as it forms a tube through which the sporoplasm travels. It pierces anything in its path and deposits the sporoplasm at a new location to begin another infective cycle.

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.

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.

Light microscopic study of four plagiorchiid trematodes infecting marine fish in the south-eastern Mediterranean Sea, Alexandria City, with descriptions of two new species

During the present investigation, a total of 220 fish specimens belonging to three different species, namely, little tunny Euthynnus alletteratus, African snook Lates niloticus, and striped red mullet Mullus surmuletus, were collected from January–November 2016 from the coasts off Abu Qir landing site, Alexandria City, south-eastern Mediterranean Sea, Egypt. The collected fish samples were dissected and examined for the presence of helminth parasites. Twenty-three out of 220 (10.45%) fish specimens were found to be naturally infected with four species of trematode parasites belonging to three different families of the order Plagiorchiida. The recovered parasite species were collected and identified by applying light microscopic examinations. The present study recorded two new parasite species, namely, Stephanostomum alletterani sp. nov. and Bathycreadium mulli sp. nov., belonging to the families Acanthocolpidae and Opecoelidae and infecting E. alletteratus and M. surmuletus, respectively and re-descriptions of the two remaining species, namely, Acanthostomum spiniceps and Aponurus mulli of the families Acanthostomatidae and Opecoelidae, respectively, to clarify the measurements of some body parts. Morphological and morphometric characterizations revealed some differences between the present species and other related species detected previously. Future studies are recommended to include advanced molecular characteristics for these species.

Characterization of 28S rRNA sequences of cestoda parasite Electrotaenia malapteruri Fritsch, 1886 from the Electric catfish Malapterurus electricus (Siluriformes: Malapteruridae)

Proteocephalids are cestoda parasites that mostly infect freshwater fish. The present study was carried out to investigate the presence of proteocephalids infecting the electric catfish Malapterurus electricus from Lake Manzala, Kafr El-Sheikh Governorate, Egypt. Morphological characterization revealed the present parasite is a cestoda belonging to the genus Electrotaenia. Morphologically, the recovered worms were characterized by an elongated body measuring 100-127 (120 ± 2) mm long and 0.92-2.11 (2.76 ± 0.1) mm wide. The anterior part of the worm was obvious terminated at a spherical scolex measured 1.12-1.91 (1.72 ± 0.01) mm long and 1.12-1.65 (1.42 ± 0.01) mm wide with a rostellum-like apical organ equipped by 5-6 irregular rows of minute hooklets, as well as four uniloculate suckers with a diameter of 0.13-0.15 (0.14 ± 0.01) mm and covered with microtriches. A long unsegmented neck was observed followed by acraspedote and anapolytic strobila consisted of 85-120 proglottids divided into 50-58 immature, 12-19 mature, and up to 49 gravid proglottids. Molecular characterization based on 28S rRNA sequences was done to confirm the taxonomy of this parasite based on its morphology. It was observed that there was a close identity up to 72.0% with other protocephalid species obtained for comparison from the GenBank. Also, the data obtained revealed that there was high blast scores and low divergence between the present parasite and previously described Electrotaenia malapteruri (acc. no. JX477434). Phylogenetic analysis showed that the parasite sequence in conjunction with existing data investigates the placement of this protocephalid species within Proteocephalidea. It was shown that the present species is deeply embedded in the genus Electrotaenia with close relationships to other Electrotaenia malapteruri as a putative sister taxon.