The buried gems of disease tolerance in animals: Evolutionary and interspecies comparative approaches: Interspecies comparative approaches are valuable tools for exploring potential new mechanisms of disease tolerance in animals: Interspecies comparative approaches are valuable tools for exploring potential new mechanisms of disease tolerance in animals.

Host defense mechanisms are categorized into different strategies, namely, avoidance, resistance and tolerance. Resistance encompasses mechanisms that directly kill the pathogen while tolerance is mainly concerned with alleviating the harsh consequences of the infection regardless of the pathogen burden. Resistance is well-known strategy in immunology while tolerance is relatively new. Studies addressed tolerance mainly using mouse models revealing a wide range of interesting tolerance mechanisms. Herein, we aim to emphasize on the interspecies comparative approaches to explore potential new mechanisms of disease tolerance. We will discuss mechanisms of tolerance with focus on those that were revealed using comparative study designs of mammals followed by summarizing the reasons for adopting comparative approaches on disease tolerance studies. Disease tolerance is a relatively new concept in immunology, we believe combining comparative studies with model organism study designs will enhance our understanding to tolerance and unveil new mechanisms of tolerance.

Therapeutic properties and molecular docking study of some phenolic compounds as anti-human lung cancer potential: A biochemical approach.

Chloroxine (5,7-dichloro-8-hydroxyquinoline) is a molecule utilized in some shampoos for the therapy of seborrheic dermatitis of the scalp and dandruff. In this study, we investigated the inhibition effects of 5,7-dichloro-8-hydroxyquinoline and methyl 3,4,5-trihydroxybenzoate compounds on the 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA Reductase) and urease enzymes. We have obtained results for the HMG-CoA Reductase and urease enzymes at the micromolar level. In our study, inhibition result of 5,7-dichloro-8-hydroxyquinoline and Methyl 3,4,5-trihydroxybenzoate on HMG-CoA reductase showed lower values 2.28 ± 0.78 and 33.25 ± 5.04 µg/ml, respectively. Additionally, inhibition result of 5,7-dichloro-8-hydroxyquinoline and methyl 3,4,5-trihydroxybenzoate on urease showed lower values 6.18 ± 1.38 and 8.51 ± 1.35 µg/ml, respectively. Molecular docking calculations were made for their biological activities were compared. In the present work, the structures of the related compounds (1 and 2) were drawn using Gaussian 09 software and done geometry optimization at DFT/B3LYP/6-31G* basis set with aforementioned program. Cytotoxicity potential of these compounds against human lung cancer demonstrated that these compounds had good cytotoxic effects. Both compounds significantly decreased lung cell viability from low doses. In addition, 100 µM dose of all compounds caused significant reductions in lung cell viability. In general, we can say that of the two tested compounds, 5,7-dichloro-8-hydroxyquinoline and methyl 3,4,5-trihydroxybenzoate have cytotoxic effects in all cell types, and this effect is particularly strong in lung cells. Activities were performed at concentrations of 10, 20, 50, 70, and 100 µl and we achieved good results. Lung cell viability (%) value was better at 100 µl concentration and IC50 of them were 54.28 and 48.05 µM.

Potency of Moringa oleifera leaf extract and silver nanoparticles against immune, microbial and HT-29 colon cancer cells growth modulation.

Moringa oleifera plant grows in many countries worldwide and being utilized as a customary medication. The current study aimed to investigate the biological effect of Moringa oleifera leaf extract (MOE) alone or in combination with silver nanoparticles (AgNPs) on colon cancer, microbial cell growth. MOE was utilized in the green synthesis of AgNPs. The characterization of AgNPs was done by UV-Vis-spectrophotometry, X-ray diffraction (XRD) and scanning electron microscopy (SEM). MOE was tested for their sugars, active biomolecules, ROS, protein contents. Results revealed that created AgNPs are about 61 nm in diameter. There were no detectable sugar and protein in MOE, but it contains ROS and active biomolecules. MOE and MOE+AgNPs exerted mild antibacterial action and increased the number of apoptotic cells and p53 protein expression of HT-29 colon cancer cells. MOE and MOE+AgNPs could arrest HT-29 cells at G2/M phase and stimulate splenic cell growth. Both extract preparations showed antioxidant activities. Because MOE and MOE+AgNP stimulated immune cells and activated apoptosis in cancer cells, these preparations can be utilized as anticancer agents.

Assessment of Hepatotoxicity Induced by Aluminum Oxide Nanoparticles in Oreochromis niloticus Using Integrated Biomarkers: Exposure and Recovery.

The hepatotoxic impacts of 2, 4, and 8 mg/L of Al2O3 nanoparticles (31.4 ± 4.8 nm) were evaluated in Oreochromis niloticus after 7 days of exposure and 15 days of recovery periods. The biochemical analysis of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in plasma showed significant increases in both 4 and 8 mg/L Al2O3 NPs exposed groups. The antioxidant biomarkers showed concentration-dependent elevations in catalase, superoxide dismutase, glutathione peroxidase activities, and thiobarbituric acid reactive substances levels. Glutathione reduced contents showed significant reductions in both 4 and 8 mg/L Al2O3 nanoparticles exposed groups. Several hepatic histopathological alterations were recorded ranging from adaptive responses (e.g. melanomacrophages aggregation) to permanent damage (e.g. necrosis). The recovery period using toxicant-free water led to an obvious reduction in the Al content in liver, liver and antioxidant enzymes in addition to regressive histopathological alterations based on the frequency of alterations occurrence and the extent of affected areas.

Morphology and molecular taxonomy of the tongue worm, genus Raillietiella (Pentastomida) from the lungs of berber skinks Eumeces schneideri (Scincidae): First report.

In the present study, pentastomids belonging to the order Cephalobaenida were isolated from the lungs of Berber skinks Eumeces schneideri (Famiy: Scincidae), which were morphologically described by light and scanning electron microscopy and taxonomically justified by 18s rDNA molecular analyses of the parasites. Seventeen host specimens were collected from well-vegetated wadis at high altitudes, Jizan, Saudi Arabia as new type locality; twelve specimens (70.59%) were infected. All of the recovered parasites were adults, possessed small broadly triangular cephalothorax flattened on the ventral surface and merged smoothly with a uniformly thick and squat abdomen and terminated in a pair of divergent lobes. The results obtained indicated that the parasites belong to the sharp-tipped posterior-hook Raillietiella spp. distinguished from other raillietiedids of the same group some important characteristic features including annulus number, shape and dimensions of the buccal cadre, copulatory spicules, and anterior and posterior hooks. The anterior hook of the female specimens (n=5) had a blade length (AB) of 135±5 (110-146) µm and shank length (BC) 158±5 (150-169) µm while the posterior hook was much larger with AB measuring 221±5 (200-236) µm and BC 286±6 (280-289) µm. For the male specimens (n=5), the anterior hook had an AB of 73±3 (72-75) µm and a BC 102±5 (100-103) µm. The posterior hook was much larger with AB 190.6±5 (190-191) µm and BC 221±5 (280-289) µm. The morphological characterization of the recovered parasites was closely similar to R. aegypti previously isolated from the same host. Sequence alignment by the maximum likelihood analysis for the data obtained from the 18S rDNA analysis of the parasites exhibits identities ranging between 88-95% with pentastomid genera recovered from the GenBank. The phylogenetic tree supported the inclusion of the parasites within the monophyletic Pentastomida clade with maximum identity to the raillietiellid species. The recovered sequences from the present study were deposited in GenBank under Accession number MK970649.1. The present molecular analysis was the first to confirm the taxonomic position of R. aegypti isolated from the host examined.

Comparative Assessment of Genotoxic Impacts Induced by Zinc Bulk- and Nano-Particles in Nile tilapia, Oreochromis niloticus.

Fish were separately exposed to 1/2 LC50/96 h values of bulk-Zn and nano-Zn for 7, 14, and 28 days. The induction of micronuclei (MN) and other eight nuclear abnormalities in erythrocytes showed marked time and size dependence. The frequencies of all nuclear anomalies were progressively elevated (p < 0.05) with increasing the time of exposure to both bulk-Zn and nano-Zn. Throughout the study periods, fish exposed to nano-Zn showed the maximum elevation in all studied nuclear anomalies. Based on the fragmented DNA values, both Zn forms induced tissue-specific DNA damage as following gills > liver > muscles. Moreover, nano-Zn exposed groups revealed a maximum percentage of DNA damage among all studied groups, especially after 14 days. The percentage of DNA damage was decreased in all tissues on the 28th day, which reflected the presence of an effective repair mechanism. Finally, nano-Zn exhibited more genotoxic effects than that of its bulk counterparts.

The Long-Term Exposure to Discharges of Sabal Drain Induces Genotoxic Effects on Oreochromis niloticus.

To study the genotoxic impacts of Sabal discharges, three sites around Sabal drain were selected and compared to a reference site (site1). Site2 was at the southern part of the main canal, site3 was at the main canal outlet, and site4 at the northern part of the main canal. Compared to the reference fish, the recorded micronuclei and other nuclear anomalies showed marked (p < 0.05) increases with different frequencies in the studied sites. The induction of nuclear deformations was as following site3 > site4 > site2 > site1. The analysis of comet assay data showed that the DNA damage (based on the percentage of tail DNA) was significantly increased and the levels of damage were associated with the distance from the main discharge point. Moreover, DNA damages showed variable percentages among the studied tissues. The gills and liver tissues collected from site3 showed the highest DNA damage compared with low muscular DNA damage.

Freshwater Clam as a Potential Bioindicator for Silver/Saponin Nanocomposites Toxicity.

Despite the progress in using silver nano products in many fields, including medicine, food, and industry, their effects on the environment need more attention. Therefore, the current study aimed to assess the effect of silver/saponin nanocomposites (Ag/S NCs) for the first time on the aquatic environment by using freshwater clam, Caelatura aegyptiaca, as a fundamental bioindicator in the freshwater system. Following the preparation and characterization of Ag/S NCs by using atomic absorption spectrophotometer, UV-Vis spectrophotometer, X-ray diffraction, transmission electron microscopy, and acute toxicity study, we exposed the clam to three different doses of Ag/S NCs (12.5, 25 and 50 mg L-1) for consecutive 6 days. All Ag/S NCs concentrations caused a significant increase in malondialdehyde and nitric oxide while induced a notable decrease in glutathione and catalase levels in all studied organs. Moreover, the histological alternations were observed in gills, labial palp, and foot tissues, particularly at dose 50 mg L-1. From the results of our work, we concluded that toxicity of Ag/S NCs on freshwater clam leads to an oxidative stress response as well as histopathological changes. Besides, we assumed that Coelatura aegyptiaca could be used as a sensitive bioindicator for monitoring water pollution caused by different nanoparticles. Therefore, we do recommend performing further studies by using fresh clam to provide a better assessment for our aquatic environment to prevent water pollution locally and globally.

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.

Morphological Re-Description and 18 S rDNA Sequence Confirmation of the Pinworm Aspiculuris tetraptera (Nematoda, Heteroxynematidae) Infecting the Laboratory Mice Mus musculus.

Aspiculuris tetraptera is a heteroxynematid nematoda infecting most of the laboratory animals, occasionally mice which represent the mostly used animal for biological, medical, and pharmacological studies. The present study aimed to investigate the prevalence of nematode parasites infection in the laboratory mice Mus musculus in Egypt. Morphologically, this oxyurid possessed four distinct cephalic papillae on a cephalic plate, with three small rudimental lips carrying two sessile poorly developed labial papillae and one pair of amphidial pores. Esophagus divided into cylindrical corpus and globular bulb. Distinct cervical alae interrupted at the level of esophago-intestinal junction forming an acute angle. At the caudal end, twelve caudal papillae in male worms while an ovijector apparatus opening and a vulva surrounded by protruded lips in females were observed. The general morphological criteria include this nematode with other Aspiculuris species which were compared in the present study. Molecular characterization based on 18SSU rDNA sequencing performed to confirm the taxonomic position of this species and to documents the morphological data. Sequence alignment detects a percent of identity up to 88.0% with other Heteroxynematidae species. Phylogenetic analysis showed that the present recorded is a putative sister taxon to A. tetraptera recorded in a previous study. The SSU rDNA sequence has been deposited in the GenBank under the accession no. MG019400.

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.

Pathogenic Potential of Fresh, Frozen, and Thermally Treated Anisakis spp. Type II (L3) (Nematoda: Anisakidae) after Oral Inoculation into Wistar Rats: A Histopathological Study.

The third-stage (L3) larvae of Anisakis are the etiological agents of human anisakiasis caused by consumption of raw or undercooked seafood infected with anisakid nematodes. Infection with these worms is associated with abdominal pain, nausea, and diarrhea and can lead to massive infiltration of eosinophils and the formation of granulomas in the gastrointestinal tract if the larvae are not removed. Food allergy affects populations worldwide, and despite several reports on the presence of the potentially zoonotic nematodes among edible fishes in Egypt, there are few immunological and molecular studies investigating the epidemiology of these parasites. Anisakidosis, a human infection with nematodes of the family Anisakidae, is caused most commonly by Anisakis spp. In the present study, seventy specimens of the European seabass Dicentrarchus labrax commercialized in Alexandria city along the Mediterranean Sea were acquired during the period from July to December, 2015. Fish were necropsied and dissected to investigate the presence of nematode larvae. Thirty fish (42.9%) of the total were parasitized by nematode larvae which were morphologically identified as Anisakis spp. Type II (L3) according to light and scanning electron microscopy. The pathogenic potential of oral inoculation of fresh, frozen, and thermally treated larvae into Wistar rats was elucidated by histological examination of their thymus and spleen. Results obtained indicated that neither cooling nor freezing of the parasite could destroy their allergenic capacity. So, it is important to create a wider awareness of this potential risk to human health. It is becoming increasingly likely that the impact of Anisakis spp. on human health has been underestimated, and it is perhaps time to consider more sweeping measures than those currently enforced to protect the public health.

Description of two equine nematodes, Parascaris equorum Goeze 1782 and Habronema microstoma Schneider 1866 from the domestic horse Equus ferus caballus (Famisly: Equidae) in Egypt.

Parasitic gastroenteritis (PGE) caused by infection of the gut with parasitic nematodes is one of the most important diseases of livestock animals from both financial and welfare perspectives. Parascaris equorum and Habronema microstoma are of the most endemic nematodes of the world which are currently the major cause of PGE of the domestic horses in Egypt. The present investigation introduced the first morphological description of these nematodes recovered from the domestic horse, Equus ferus caballus (Equidae), in Egypt by light and scanning electron microscopy. Seven P. equorum (fifth stage) and 18 adults of H. microstoma were recovered from the gastrointestinal tracts of four young domestic horses collected during the year of 2015. Microscopic examination of the isolated fifth stage P. equorum revealed that it possessed a long body with a broad anterior end equipped by large shamrock-like lips with deep transverse groove on medial surface set off from the rest of the body by a deep post-labial constriction giving the body a shouldered appearance. The total body length was 12-15 (14 ± 2) cm for males and 13-18 (16 ± 2) cm for females. Lips were three in number in the form of one dorsal and two sub-ventral surrounding the central stoma. The isolated adult worms of H. microstoma were whitish in color narrowed slightly at the anterior end. Single lateral ala in the cephalic region in both sexes was observed. The buccal vestibule was markedly thickened and equipped by two tridentate teeth. The adult worms had two bilobed lateral lips surrounding the mouth with four sub-median cephalic papillae and two amphids. The males were 14.5-18.0 (17.2 ± 0.3) mm long and 1.23-1.57 (1.42 ± 0.3) mm wide. The posterior end was spirally coiled and had wide caudal alae. The spicules were unequal. The females were 13.5-21.0 (16.2 ± 0.3) mm long and 1.55-1.75 (1.69 ± 0.3) mm wide. The anal pore had a thin upper rim and was located 177.0 µm from the posterior end.

Henneguya collaris sp. nov., (Myxosporidia), parasite of the Greenband Parrotfish Scarus collana Rüppell, 1835 (Actinopterygii, Scaridae) from the Red Sea, Egypt. A light and electron microscopic study.

The phylum Myxozoa comprises more than 2180 species, almost all of which are considered to be obligate parasites of aquatic fishes. In the present study, Henneguya collaris sp. nov. is the first described histozoic myxozoan species of the genus Henneguya infecting the kidney of the greenband parrotfish Scarus collana (Actinopterygii, Scaridae). One hundred and eighty specimens of fish were collected randomly during the period from September 2014 to October 2015 from boat landing sites and the market places at Hurghada City along the Red Sea in Egypt. Of these, 90 (50 %) specimens were infected. Light microscopic examination showed that the infection was detected as mature spores with two polar capsules regularly arranged at the anterior pole of each spore and extruded polar filaments free in the kidney tissue. The spore body was oval in shape, measured 7.1 ± 0.2 (6.2-8.4) µm in length and 6.3 ± 0.2 (5.8-7.0) µm in width, with a bifurcated caudal process of equal length, reaching 6.3 ± 0.2 (5.8-7.0) µm in length. Polar capsules were 3.4 ± 0.2 (3.0-4.2) µm in length and 1.9 ± 0.2 (1.6-2.4) µm in width with 6-8 (10) turns of polar filaments. Ultrastructural analysis showed that the spore development was asynchronous. Sporogenesis, capsulogensis, valvogenesis, and spore maturation of the present parasite were also described. The present species was compared morphologically with the spore characteristics of the most similar species of Henneguya spp. recorded previously from different geographical areas taking into account the stage and dimensions of the spore body, tails, and polar filament coils, including their number and the most important characteristic features that distinguish them from the present species. Considering the data obtained, the material described herein represents a new species and the name Henneguya collaris sp. nov. is proposed.

Testicular myxosporidiasis and ultrastructural characteristics of Myxobolus bufonis (Myxobolidae) infecting the Egyptian toad Bufo regularis (Bufonidae). A light and electron microscopic study.

The phylum Myxozoa comprises more than 2180 species, almost all of which are considered to be obligate parasites of aquatic fishes and amphibians. They are dangerous pathogens responsible for severe economic losses. From March to September 2014, 40 adult male Bufo regularis (Bufonidae) captured from different areas at Giza province, Egypt, were surveyed for myxosporean parasitic infection. Of these, 22 (55%) were infected by histozoic plasmodia, which produced spores after rupture belonging to Myxosporidia. The present investigation introduced a new data for the recorded parasite observed by light and transmission electron microscopy. The infection was diagnosed as large clusters of macroscopic plasmodia embedded in the testicular tissue causing distortion at the site of infection. The host reaction was manifested by the encapsulation of the plasmodia with a thick layer of connective tissue. Plasmodia were whitish in color, elliptical to ovoid in shape measuring 0.54 ± 0.2 (0.34-0.63) mm in diameter. The spores were subspherical, reaching 7.1 ± 0.2 (6.2-8.4) µm in length and 6.3 ± 0.2 (5.8-7.0) µm in width with two equal-sized polar capsules regularly arranged at the anterior pole of each spore. They were 3.4 ± 0.2 (3.0-4.2) µm in length and 1.9 ± 0.2 (1.6-2.4) in width with 6-8 turns of polar filaments. Ultrastructural analysis showed that the plasmodia were surrounded by a plasma 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. Sporogenesis, capsulogenesis, valvogenesis, and spore maturation of the present parasite were also described.

New host records of three juvenile nematodes in Egypt: Anisakis sp. (Type II), Hysterothylacium patagonense (Anisakidae), and Echinocephalus overstreeti (Gnathostomatidae) from the greater lizard fish Saurida undosquamis of the Red Sea.

Three juvenile nematode parasites were collected naturally from 90 (75 %) out of 120 specimens of the marine greater lizard fish Saurida undosquamis captured from water coasts at Hurghada City along the Red Sea in Egypt during the period from September 2013 to April 2014. Worms were identified on the basis of light and scanning electron microscopy. Two of the recovered worms were isolated from the peritoneal cavity of the infected fish around the wall of the stomach as encapsulated larvae. The anisakid juvenile Anisakis sp. (Type II) was characterized by an anteroventrally triangular mouth, with a boring tooth; its postanal tail was rounded, without a terminal mucron or spine. The gnathostomatid Echinocephalus overstreeti was characterized by the presence of a cephalic bulb armed with six transverse rows of spines which were slightly more compact near the anterior end of bulb with maximal separation near the midbulb; the cephalic bulb terminated at a pseudolabia which situated dorsoventrally and reached its greatest width at the posterior one third of the body, The postanal tail terminated at a pointed mucron. The third juvenile species, Hysterothylacium patagonense (Anisakidae), was isolated from the intestine of the infected fish; they are characterized by a small-sized body with a conical tail provided by a nodulose apex, and the anterior end was equipped with three lips. A dorsal lip slightly smaller than the two subventrals left a deep postlabial groove and prominent lateral flanges in between, and the proximal part of each lip was smooth. The three described species were compared morphologically and morphometrically with some of the previously recorded species of the same genus. From this comparison, the similarity and variations between these species were described and concluded that the present study should be considered as a new host record in Egypt.

Molecular characterization and new geographical record of Lecithochirium priacanthi (Digenea: Hemiuridae) infecting the moontail bullseye fish Priacanthus hamrur (Perciformes: Priacanthidae) from the Red Sea, Egypt.

Sixty specimens of the moontail bullseye Priacanthus hamrur were collected at Coasts of Suez Gulf, Red Sea (Egypt) during the four different seasons of the whole year 2014 and necropsied to study the infection with metazoan parasites. Twenty-one out of 60 examined fish specimens (infection rate of 33.33 %) were found to be naturally infected by the hemiurid digenean parasite Lecithochirium priacanthi. The large-sized fish reaching 15-30 (23.5 ± 4.8) cm were more intensively infected than the smaller ones. A definite seasonal effect was observed as winter was found to be the season of severe parasitic infections, while midsummer was the lowest one. The morphological and morphometric characterization of this parasite were examined by light and scanning electron microscopy. The adult worms had an elongated body measuring 1.93-2.54 (2.11 ± 0.20) mm in length and 0.61-0.72 (0.67 ± 0.02) mm in width. The body was characterized by the presence of a sub-terminal oral sucker with diameters reaching 0.12-0.16 (0.14 ± 0.02) mm. The ventral sucker measured 0.32-0.45 (0.38 ± 0.02) mm in diameter. The body was supplied by a short retracted portion with a blunt end that measured 0.48-0.61 (0.56 ± 0.02) mm in length and 0.28-0.35 (0.32 ± 0.02) mm in width. Morphological results of the present parasite were compared with other related species described previously from Perciformes. Molecular characterization based on small subunit ribosomal DNA was done to confirm the obtained morphological and morphometric results. A preliminary genetic comparison between SSU rDNA of this parasite and other species of Hemiuridae places the present specimen as a putative sister taxon to Lecithochirium grandiporum and Lecithochirium caesionis. The finding of L. priacanthi in Egyptian marine water fish represents a new geographical record for this parasite.

Cytokine signature and antibody-mediated response against fresh and attenuated Anisakis simplex (L3) administration into Wistar rats: implication for anti-allergic reaction.

The third larval stage (L3) of Anisakis simplex (Anisakidae) is one of the zoonotic parasitic nematodes in the musculature and visceral organs of marine fishes belonging to family Moronidae. The consumption of these high-commercial-value fish is widespread in many countries around the Mediterranean Sea including Egypt. The presence of these larvae in fish muscles poses a potential consumer hazard due to the parasite's ability to cause anisakidosis. Forty-two out of 60 (70%) of the European seabass Dicentrarchus labrax were found to be naturally infected by L3 of A. simplex in the form of encapsulated juveniles in the fish musculature. Morphological examination of recovered parasites by light and scanning electron microscopy showed that, in general, all specimens examined closely resembled A. simplex (L3). To evaluate the allergenicity of this nematode, white blood cell count; levels of T helper 1 (Th1) [interferon (IFN)-γ and tumor necrosis factor (TNF)-α)], Th2 [IL-4, IL-5, and IL-6], and Th17 [IL-17] related cytokines; total IgE and IgG antibodies; and nitric oxide (NO) were measured in the plasma of Wistar rats sensitized by oral inoculation with fresh, frozen, and heat-treated A. simplex L3 or rats intraperitoneally injected with L3 crude extract. Rats sensitized with fresh and frozen L3 larvae produced significantly higher levels of IFN-γ, IL-5, IL-17, and total IgE as compared to control rats. Heat-treated larvae administration resulted in a significant rise of IFN-γ, TNF-α, IL-5, and total IgE in comparison to control rats. Intraperitoneal sensitizations enhanced release of IFN-γ, TNF-α, and total IgE. Oral sensitization led to a significant production of NO. Thereby, frozen or cooked larval L3 cannot inhibit the release of Th-related cytokines and IgE, which might impact on the overall anti-parasitic immunity.

Hysterothylacium aduncum (Nematoda, Anisakidae) with a new host record from the common sole Solea solea (Soleidae) and its role as a biological indicator of pollution.

Hysterothylacium aduncum (Nematoda, Anisakidae) was isolated from the intestine of the common sole Solea solea (Family, Soleidae) collected from coasts along Alexandria City at the Mediterranean Sea in Egypt, during the period from May to September 2013. Light and scanning electron microscopy revealed that this nematode parasite belongs to the family Anisakidae in the genus Hysterothylacium. The type species is named H. aduncum, based on the presence of three interlocked lips with the interlabium in between, the presence of cephalic papillae, and large numbers of caudal papillae in males. Body measurements showed that the male worms were smaller than females measuring 13.9-18 mm (16.2 ± 0.2) in length and 0.26-0.34 mm (0.30 ± 0.01) in width. Females measured 20.5-24.5 mm (22.7 ± 0.2) in length and 0.41-0.52 mm (0.45 ± 0.01) in width. The morphological characteristics of this species was confirmed by molecular analysis of 18S rDNA for these parasites followed by comparison between sequence data for them with those obtained from the Genbank showing that H. aduncum is deeply embedded in the genus Hysterothylacium with a sequence similarity between 95.5-94.3 % with close relationships to other H. aduncum specimens and Hysterothylacium sp.. Furthermore, it was shown that this parasitic nematode is able to accumulate larger concentrations of heavy metals such as Fe, Cu, Cd, and Ni within its tissues than of its host fish and thus it can be used as a useful bio-indicator of water pollution.

Twelve myxosporean species of the family Myxobolidae infecting freshwater fishes of the River Nile, Egypt, with the description of four novel species.

Myxosporidian parasites infecting fish are very dangerous parasites causing severe damage to a large number of economically important fishes especially in aquaculture. A survey of myxosporean parasites infecting four species of fishes from the River Nile in Egypt is conducted. One hundred and ninety-five out of 316 fish specimens with a percentage of 61.7% were found to be naturally infected with these parasites. Light microscopic examination of different tissues revealed the presence of 12 myxosporean species belonging to the family Myxobolidae. Four of the identified species are novel and the other eight species are redescribed. Myxidium sp.nov. a coelozoic species inhabiting the gallbladder of Labeo niloticus with its mature spores float free in bile was detected. These spores possess a fusiform, straight, or slightly crescentic shape with less pointed ends and two equal polar capsules. Three novel histozoic Myxobolus species infecting Oreochromis niloticus were identified. Myxobolus sp(1).nov. is a species inhabiting kidney tissue with ovoid spores exhibiting a small intercapsular appendix. Myxobolus sp(2).nov. and Myxobolus sp(3).nov. recovered from kidney and intestinal tissues. Spores of Myxobolus sp(2).nov. are elliptical in shape with an anterior end wider than posterior one. Their two polar capsules are ovoid to pyriform occupied nearly the first third of the spore body. Spores of Myxobolus sp(3).nov. are broader than long with nearly rounded or ovoid two polar capsules. Eight species of the recovered myxosporean parasites are redescribed, Myxobolus niloticus Fahmy et al., 1971 from pectoral, dorsal, and tail fins of L. niloticus, Henneguya suprabranchiae Landsberg, 1987, and Henneguya branchialis Ashmawy et al., 1989 are recovered from the gills and suprabranchial organ of the catfish Clarias gariepinus, respectively, Myxobolus naffari Abdel-Ghaffar et al., 1998 and Myxobolus imami Ali et al., 2002 are found in the kidney of Barbus bynni and L. niloticus, Myxobolus caudatus Ali et al. & Parasitol Res (2002) from Tail fin of B. bynni, Myxobolus fomenai Abdel-Ghaffar et al., 2008 from kidney and intestinal tissues of O. niloticus, Thelohanellus niloticus Abdel-Ghaffar et al., 2012 are observed in the gills of L. niloticus.