Skip to main content
Originally, Myxobolus fahmii was described from the gills of Barbus bynni collected from the Nile River, Egypt. The original study provided only mensural characteristics of the spores and referred to gill lamellae as the site for the... more
Originally, Myxobolus fahmii was described from the gills of Barbus bynni collected from the Nile River, Egypt. The original study provided only mensural characteristics of the spores and referred to gill lamellae as the site for the infection. In this study, B. bynni were collected from almost the same locality, with a similar parasite being found. Our investigations enabled us to determine the precise infection site, which corresponded with the "filamental vascular type" and to provide, for the first time, information on pathogenicity and on the seasonal variation in the prevalence of M. fahmii in gills. The infection was recorded as whitish ellipsoidal plasmodia within the afferent artery of the gill filaments. Due to continuous growth of the plasmodia, gill lamellae were atrophied and obliterated at the plasmodium site. Spores were drop to ovoid shaped with a mean length of 11 μm and mean width of 8 μm. Polar capsules were pear shaped, measuring 7 μm in length × 3.0 μm...
Babesia divergens is an intraerythrocytic parasite which is capable of infecting a wide range of vertebrates causing huge economic losses. Histopathological, hematological and biochemical changes during B. divergens infection in female... more
Babesia divergens is an intraerythrocytic parasite which is capable of infecting a wide range of vertebrates causing huge economic losses. Histopathological, hematological and biochemical changes during B. divergens infection in female Meriones ungliculatus were reported. Animals were challenged with 5 × 10(6) B. divergens-infected erythrocytes. Parasitemia were maximum at day 5 postinfection where all gerbils died. Infection of gerbils with Babesia induced a significant decrease in erythrocytic count as well as the hemoglobin concentration and hematocrit percentage but leucocytes were increased significantly when compared to uninfected gerbils. Liver enzymes aspartate aminotransferase (AST) and aniline aminotransferase (ALT) were significantly increased while albumin and total bilirubin were significantly decreased at day 5 postinfection with B. divergens-infected erythrocytes. Histopathological scores of inflammation after infection of gerbils were done using Ischak's activity...
The present study was carried out as part of an ongoing general survey seeking to uncover protozoan parasites infecting cultured tilapia in the central region of Saudi Arabia. In the sample of 400 specimens of tilapia (Oreochromis... more
The present study was carried out as part of an ongoing general survey seeking to uncover protozoan parasites infecting cultured tilapia in the central region of Saudi Arabia. In the sample of 400 specimens of tilapia (Oreochromis niloticus) 30 were infested with Ambiphrya ameiuri simultaneously with Vorticella sp. Morphometric criteria were used to describe and identify these species and this study presents the first records of these species among cultured fish in Saudi Arabia.
Myxozoans, a diverse group of microscopic obligate endoparasites, can cause diseases in a number of economically important fish, including the marbled spinefoot Siganus rivulatus. To date, only 1 myxozoan, Zschokkella helmii, has been... more
Myxozoans, a diverse group of microscopic obligate endoparasites, can cause diseases in a number of economically important fish, including the marbled spinefoot Siganus rivulatus. To date, only 1 myxozoan, Zschokkella helmii, has been reported to infect S. rivulatus. Here we describe another myxozoan detected in S. rivulatus. Investigations of 40 marbled spinefoot fish caught from the Red Sea coast, Jeddah, Saudi Arabia, revealed clusters of parasitic spores in the kidney. Light microscope examination of the native spores revealed sub-spherical, mature spores with smooth shell valves. The 2 polar capsules were equal in size, and the polar filament was perpendicular to the longitudinal axis of the polar capsules. Histopathological examinations of the infected kidneys demonstrated the presence of both spores and developmental stages in the lumen of the renal tubules without any pathological effect. Electron microscopy investigations showed maturing spores composed of 2 valvogenic cell...
Increasing evidence critically implicates miRNAs in the pathogenesis of diseases, but little is known in context with infectious diseases. This study investigates as to whether the testosterone-induced persistent susceptibility to... more
Increasing evidence critically implicates miRNAs in the pathogenesis of diseases, but little is known in context with infectious diseases. This study investigates as to whether the testosterone-induced persistent susceptibility to blood-stage malaria of Plasmodium chabaudi coincides with changes in miRNA expression of the anti-malaria effectors sites spleen and liver. Female C57BL/6 mice were treated with vehicle or testosterone (T) for 3 weeks. Then, T treatment was discontinued for 12 weeks before challenge with 10(6) P. chabaudi-parasitized erythrocytes. The miRNA expression was examined after 12 weeks of T withdrawal and during infections at peak parasitemia on day 8 p.i. using miRXplore™ microarray technology. P. chabaudi infections induce an organ-specific response of miRNA expression. We can identify 25 miRNA species to be downregulated by more than 2-fold in the spleen and 169 miRNA species in the liver. Among these 194 miRNA species, there are 12 common miRNA species that are downregulated by 0.48-0.14-fold in both spleen and liver, which are miR-194, miR-192, miR-193A-3P, miR-145, miR-16, miR-99A, miR-99B, miR-15A, miR-152, let-7G, let-7B, and miR-455-3P. Only in the liver, there is an upregulation of the miR-142-5p by 2.5-fold and miR-342-3p by 5.1-fold. After 12 weeks of T withdrawal, the spleen exhibits only the miR-200A that is upregulated by 2.7-fold. In the liver, miR-376B, miR-493*, and miR-188-3P are upregulated by 2.4-fold, 2.2-fold, and 2.1-fold, respectively, and miR-347, miR-200A, and miR-200B are downregulated by approximately 0.4-fold. Upon infection, however, these changes are not sustained, i.e., the miRNA expressions of both spleen and liver of T-pretreated mice exhibit the same response to P. chabaudi malaria as that of vehicle-treated control mice. Our data suggest (1) that the P. chabaudi-induced downregulation of miRNA expression in spleen and liver is required to allow the upregulation of their numerous target genes in response to infection, and (2) that the T-induced persistent susceptibility to P. chabaudi does not affect the responsiveness of miRNA expression in spleen and liver to blood-stage malaria.
A new microsporidian species of the genus Glugea Thélohan, 1891 parasitising the marine teleost fish Cephalopholis hemistiktos Rüppell, collected from the Red Sea in Saudi Arabia, is described on the basis of microscopic and molecular... more
A new microsporidian species of the genus Glugea Thélohan, 1891 parasitising the marine teleost fish Cephalopholis hemistiktos Rüppell, collected from the Red Sea in Saudi Arabia, is described on the basis of microscopic and molecular procedures. Spherical and whitish xenoma were observed adhering to the intestinal wall. The numerous spores contained within these xenoma, were ovoid to pyriform and measured 4.3-6.0 µm (5.1 µm) in length and 1.8-2.9 µm (2.2 µm) in width. The spore's wall was composed of two thick layers, which were thinner in the area contacting the anchoring disk. The latter appeared at the spore's anterior pole, in an eccentric position to the longitudinal axis. A lamellar polaroplast surrounded the uncoiled portion of the polar filament projected to the basal region of the spore, giving rise to 26-29 turns with winding from the base to the anterior zone of the spore. The posterior vacuole, located at the spore's posterior pole, and surrounded by the polar filament coils, was irregular and composed of light material. Molecular analysis of the rRNA genes, including the ITS region, was performed using maximum parsimony, neighbour-joining and maximum likelihood methods. The ultrastructural features observed, combined with the phylogenetic data analysed, suggest this parasite to be a new species of the genus Glugea. This is the first species of this genus to be reported from Saudi Arabia and is herein named Glugea nagelia sp. n.
Testosterone (T) is known to masculinize the female phenotype of the liver, evidenced as up- and down-regulated expressions of male- and female-predominant genes, respectively, involved in hepatic metabolism. This study is aimed at... more
Testosterone (T) is known to masculinize the female phenotype of the liver, evidenced as up- and down-regulated expressions of male- and female-predominant genes, respectively, involved in hepatic metabolism. This study is aimed at identifying epigenetic modifications of promoters of these differently expressed genes in the liver after masculinization by T of adult female C57BL/6 mice using methylated DNA immunoprecipitation and NimbleGen microarrays. Among the 17,354 promoters examined, 82 promoters in the liver have been identified to be significantly changed by T (p<0.05), with 47 and 35 promoters exhibiting increased and decreased DNA methylation, respectively. Most of these promoters display the changes of DNA methylation in their Ups-regions, which are between +500 and +2000 bp upstream from the transcription start site (TSS) of the genes. Less T-induced modifications have been detected in the Cor-regions of the promoters, i.e., +500 to -500 bp around the TSS. Only 13 and 7 Cor-promoters are hyper- and hypo-methylated, respectively, among which are 10 hyper- and 5 hypo-methylated promoters of genes with annotated functions. Surprisingly, the promoters are largely unmethylated in those genes whose expression has been previously found to be permanently deregulated by T in the liver, as e.g. the T-upregulated male-predominant genes Cyp7b1, Cyp2d9, Cyp4a10, Ugt2b1, Ugt2b38, Hsd3b5, Slco1a1 as well as the T-downregulated female-predominant genes Cyp2b9, Cyp2b13, Cyp3a41, Cyp3a44, Fmo3, Sult2a2, respectively. Though methylatable, the promoter DNA of Ar, Esr1, and Esr2 remained unaffected by T. However, T decreases DNA-methylation of the Cor-promoter region of Ddc encoding the AR-coactivator dopa decarboxylase. Among the identified 15 Cor-promoters of genes with annotated functions are also those of Defb43, Cst11, and Sele involved in innate immunity. Our data support the view that T may exert long-lasting epigenetic effects on functions of the liver-inherent immune system.
Eimeria infection was surveyed among farm and house reared broiler chicks. For the first time, Eimeria tenella was recoded among chicken in Saudi Arabia. The prevalence of the infection was 80% among the house reared chicks while no... more
Eimeria infection was surveyed among farm and house reared broiler chicks. For the first time, Eimeria tenella was recoded among chicken in Saudi Arabia. The prevalence of the infection was 80% among the house reared chicks while no infection was reported among the farm chicks. The younger chicks were more susceptible to the infection than the older ones.
During the present study seasonal prevalence of Microsporidium sp. infecting lizard fish, Saurida undosquamis were reported. Infection was reported as whitish cysts in the skeletal muscles. The mature spores were ovoid to pyriform with... more
During the present study seasonal prevalence of Microsporidium sp. infecting lizard fish, Saurida undosquamis were reported. Infection was reported as whitish cysts in the skeletal muscles. The mature spores were ovoid to pyriform with large vacuole at their ends. Sixty out of 200 fish were infected (30%). The highest infection was in autumn (64%) while the lowest one was in
Six Myxobolus species are described from Nile fish, five of which are new and one is redescribed: M. naffari Abdel Ghaffar et al., 1998 was recovered from the gills of Labeo niloticus and the mouth of Barbus bynni; M. caudatus sp. n. was... more
Six Myxobolus species are described from Nile fish, five of which are new and one is redescribed: M. naffari Abdel Ghaffar et al., 1998 was recovered from the gills of Labeo niloticus and the mouth of Barbus bynni; M. caudatus sp. n. was observed in the tail fin of B. bynni; M. fahmii sp. n. occurred in the gills of B. bynni; M. imami sp. n. was found in the kidney of L. niloticus; M. intestinalis sp. n. was recorded from the intestine of B. bynni; and M. perforata sp. n. was found in the internal surface of the operculum of Hydrocynus forskalii. The histological effects of some of the Myxobolus infections present are described.
The present study sought to assess the potential of the cestode Hymenolepis diminuta as a bioindicator for lead accumulation in two industrial areas of the city of Riyadh, Saudi Arabia. Rats (Meriones libycus) were collected from two... more
The present study sought to assess the potential of the cestode Hymenolepis diminuta as a bioindicator for lead accumulation in two industrial areas of the city of Riyadh, Saudi Arabia. Rats (Meriones libycus) were collected from two sites (industrial area II and Salbukh) in Riyadh. In the industrial area II, the mean levels of lead concentrations were found to be 1.96, 1.92, 1.4 and 30.72 μg/g in the rats' liver, kidney and intestine, and in H. diminuta, respectively. In Salbukh, meanwhile, the lead concentrations were 1.63, 1.52, 1.20 and 21.31 μg/g in the rats' liver, kidney, and intestine, and in H. diminuta, respectively. In addition, in industrial area II, compared with the liver, kidney and intestine of their host, the bioconcentration factors of lead were found to be, respectively, 15.6, 16 and 21.9 times higher in H. diminuta, and were 7.5, 8, and 10.2 times higher in the same organs compared to H. diminuta in Salbukh. The present study, therefore, proved that H. di...
Published online: 13 November 2007 © Springer-Verlag 2011 ... Erratum to: Parasitol Res (2007) 102:205–209 DOI 10.1007/s00436-007-0748-8 ... The original version of this article unfortunately contained a mistake. The schematic diagram and... more
Published online: 13 November 2007 © Springer-Verlag 2011 ... Erratum to: Parasitol Res (2007) 102:205–209 DOI 10.1007/s00436-007-0748-8 ... The original version of this article unfortunately contained a mistake. The schematic diagram and the legend of Fig. 9 in the paper are ...
This study presents the ultrastructural characteristics of sporogenesis in the genus Myxobolus which infects four economically important Egyptian fishes: Oreochromis niloticus niloticus, Barbus bynni, Labeo niloticus and Hydrocynus... more
This study presents the ultrastructural characteristics of sporogenesis in the genus Myxobolus which infects four economically important Egyptian fishes: Oreochromis niloticus niloticus, Barbus bynni, Labeo niloticus and Hydrocynus forskalii, specimens of which were collected at Giza city. Although the cysts were observed in different organs, the pattern of sporogenesis was the same. Moreover, the sporogenesis found in the present study followed the usual pattern valid for most of the myxosporean genera studied.
Redescription of Myxobolus niloticus Fahmy et al. 1971, from tail fin of Labeo niloticus is presented in this paper to complete the Fahmy et al. description. The seasonal variation and the histological impacts of the parasite are... more
Redescription of Myxobolus niloticus Fahmy et al. 1971, from tail fin of Labeo niloticus is presented in this paper to complete the Fahmy et al. description. The seasonal variation and the histological impacts of the parasite are described as well. In the present work, new data on the spore morphology were obtained with the use of light microscopy, which made it possible to be redescribe. The prevalence of infection was 20.8%. The infection caused mild fin lesions, which can be negligible. The low-intensity infection found in the present study caused only minor deformity of the fins.
A new myxosporean, Zschokkella egyptica n. sp. was found in the gallbladder of two hosts: the eel catfish Plotosus lineatus and the freckled goat fish Upeneus tragula from the Red Sea at Suez City, Egypt. The plasmodia were polysporic,... more
A new myxosporean, Zschokkella egyptica n. sp. was found in the gallbladder of two hosts: the eel catfish Plotosus lineatus and the freckled goat fish Upeneus tragula from the Red Sea at Suez City, Egypt. The plasmodia were polysporic, kidney to elliptical shaped with hairy holdfast projection and measured 109 x 70 microm. Mature spores were fusiform with 9 to 11 longitudinal striations. The mean spore dimensions were 13.0 x 10.5 microm. Spherical polar capsules are 4.8 microm in diameter; the polar filament showed four turns and were arranged perpendicular to the longitudinal axis of the capsule.
Intestinal coccidiosis of rabbits induced by E. coecicola causes enormous economic losses in rabbit farms. Here, we investigate the effect of E. coecicola on the liver of the rabbit Oryctolagus cuniculus. On day 7 p.i., fecal expulsion of... more
Intestinal coccidiosis of rabbits induced by E. coecicola causes enormous economic losses in rabbit farms. Here, we investigate the effect of E. coecicola on the liver of the rabbit Oryctolagus cuniculus. On day 7 p.i., fecal expulsion of E. coecicola oocysts is maximal and rabbits have lost approximately 25% of their weight. The liver, though not targeted by parasites, exhibits several signs of moderate inflammations, i.e., inflammatory cellular infiltrations around the central vein, dilatated blood sinusoids, increase in vacuolated hepatocytes, hypertrophic Kupffer cells, and lipid peroxidation as well as decreases in catalase and superoxide dismutase activities. Liver injuries are also indicated by an increase in blood plasma, by an increase in liver enzymes such as alanine transaminase, aspartate transaminase, alkaline phosphatase, and gamma glutamyl transferase, and a decrease in total protein and albumin. Circulating neutrophils have increased from 61% on day 0 p.i. to 71.3% on day 7 p.i., while lymphocytes are decreased from 37% to 26%. Agilent two-color oligo microarray technology, in combination with quantitative PCR, reveals that the expressions of 56 genes are upregulated and that of 22 genes are downregulated in the liver. The genes are largely involved in metabolism, calcium homeostasis, transport, and diverse signaling processes in the liver. In addition, numerous genes encoding for different regions of T-cell receptor as well as IgM, IgG, and IgA antibodies are both up- and downregulated in the liver by E. coecicola infections. The latter data suggest that the liver is not only 'passively' inflamed by intestinal infections with E. coecicola but rather is actively involved in the host defense against the intestinal Eimeria parasites.
Here, we investigated the effect of the trace element selenium (Se) on course and outcome of Eimeria-paplllata-induced coccidiosis in mice. Male mice were fed on Se-adequate (0.15 ppm), Se-deficient, and Se-high diets (1.0 ppm) for 6... more
Here, we investigated the effect of the trace element selenium (Se) on course and outcome of Eimeria-paplllata-induced coccidiosis in mice. Male mice were fed on Se-adequate (0.15 ppm), Se-deficient, and Se-high diets (1.0 ppm) for 6 weeks. Mice were orally infected with 1,000 oocysts. The prepatent period lasts for 3 days, but the course of infections varied. At Se-adequate diet, the maximum fecal output of oocysts amounted to 68,300 ooccysts/g feces on day 5 p.i.. However, fecal shedding of oocysts was accelerated in mice on Se-deficient diet and occurred already on day 4 p.i.. By contrast, maximal shedding is impaired in mice on high-Se diet, which takes place on day 5 p.i., but with a decreased output of only 7,300 oocysts/g feces. Light microscopy reveals that all developmental stages are affected: meronts, micro- and macrogamonts, and developing oocysts are increased in comparison with mice fed on selenium-adequate diet. At high Se, the number of parasitic stages in the jejunum is substantially higher than at Se-deficient diet. Se does not affect the number of jejunal Alcian blue-stained goblet cells. Se deficiency increased the number of apoptotic cells in the jejunum. Substantially increased histological injury scores reveal more injuries in jejunum tissue infected by E. papillata. Our data indicate that high dietary Se exerts potential anticoccidial activity. This may be taken advantage of in control measures towards Eimeriosis as a feed additive, potentially alleviating the need for concomitantly utilized anti-coccidial drugs in the feed.
A new microsporidian that infects the lizardfish Saurida undosquamis (Richardson, 1848) that are caught in the Arabian Gulf in Saudi Arabia is described here. This parasite invades the skeletal muscle of the abdominal cavity forming... more
A new microsporidian that infects the lizardfish Saurida undosquamis (Richardson, 1848) that are caught in the Arabian Gulf in Saudi Arabia is described here. This parasite invades the skeletal muscle of the abdominal cavity forming white, cyst-like structures containing numerous spores. The prevalence of the infection was 32·1% (135/420). The spores were oval to pyriform in shape and measured approximately 3·3 μm×2·0 μm. The developing spores were found within parasitophorous vacuoles. In mature spores, the polar filament was arranged into 5 coils in a row. Molecular analysis of the rRNA genes, including the ITS region, and phylogenetic analyses using maximum parsimony, maximum likelihood, and Bayesian inference were performed. The ultrastructural characteristics and phylogenetic analyses support the recognition of a new species, herein named Heterosporis saurida n. sp.
Isospora bors n. sp. (Apicomplexa: Eimeriidae) is described from 6 of 30 (20%) Baiuch rock gecko Bunopus tuberculatus Blanford in Saudi Arabia. Sporulated oocysts are subspheroidal to spheroidal, 18 × 16 (17-20 × 15-17) μm, with a... more
Isospora bors n. sp. (Apicomplexa: Eimeriidae) is described from 6 of 30 (20%) Baiuch rock gecko Bunopus tuberculatus Blanford in Saudi Arabia. Sporulated oocysts are subspheroidal to spheroidal, 18 × 16 (17-20 × 15-17) μm, with a bilayered, smooth, yellow-orange wall, without striae or micropyle. Polar body and oocyst residuum, both absent. Sporocysts are ovoidal, 10 × 7 (9-11 × 6-9) μm, with a Stieda body and sporocyst residuum. Endogenous stages developed in the cytoplasm of epithelial cells of the small intestine and above the host cell nucleus.
This paper describes the fine structure of oocysts of Nematopsis sp. (Apicomplexa, Porosporidae) found in the abductor muscles of seawater clams, Meretrix meretrix (Linnaeus, 1758) (Veneridae), collected near the city of Dammam (6 degrees... more
This paper describes the fine structure of oocysts of Nematopsis sp. (Apicomplexa, Porosporidae) found in the abductor muscles of seawater clams, Meretrix meretrix (Linnaeus, 1758) (Veneridae), collected near the city of Dammam (6 degrees 17'0"N, 50 degrees 12'0"E) in the Arabian Gulf off the coast of Saudi Arabia. Oocysts of an ellipsoidal shape were found among myofibrils of the abductor muscles of infected clams. Each oocyst is composed of an oocyst wall surrounding a single uninucleate vermiform sporozoite located in the lumen of the oocyst wall. The thin oocyst wall (0.70-0.85 microm thick) is composed of homogenous electron-lucent material formed by three layers of equal-thickness. The oocyst wall contains a plano-convex opercular-like structure about 2.5 microm in diameter and 0.75-0.90 microm thick, composed of a homogenous material with moderate electron density. The oocyst is of an ellipsoidal shape and is 15.6 +/- 0.6 microm long and 11.1 +/- 0.7 microm wide. Externally, the oocyst wall is surrounded by a complex dense network of numerous anastomosed microfibrils, which are attached to the oocyst wall, forming 2-3 layers and extending towards the periphery, at some points penetrating amongst the host cells. The myofibrils in some cases show evident aspects of lysis as a consequence of the appearance of lysosome-like vesicles. Lacking knowledge of a complete life cycle and/or molecular data precluded the conclusive identification of this species.
We describe the ultrastructural characteristics and histological impacts of Myxobolus naffari Abdel-Ghaffar et al., 1998, which infects the Nile fish Labeo niloticus. The prevalence of infection was 65%, with the maximum rate occurring... more
We describe the ultrastructural characteristics and histological impacts of Myxobolus naffari Abdel-Ghaffar et al., 1998, which infects the Nile fish Labeo niloticus. The prevalence of infection was 65%, with the maximum rate occurring during winter and a lower rate during summer. The histological impacts were manifested as a fusion of the gill epithelia, hyperplasia at the ends of the plasmodia, and atrophy of the external surface of the plasmodia. The ultrastructural study revealed that the plasmodial wall was composed of a single unit membrane and bound externally by a thick layer of collagen fibers. The earliest recognizable stage was the disporous pansporoblast. The development of the parasite was asynchronous, with mature and immature spores randomly distributed throughout the plasmodium.
... Etymology: The parasite is named for Prof. Mansour El-Matbouli in recognition of his valuable contribution to myxozoan research. ... Etymology: The parasite is named for Prof. Fathy Abdel-Ghaffar,Professor of Parasitology, Cairo... more
... Etymology: The parasite is named for Prof. Mansour El-Matbouli in recognition of his valuable contribution to myxozoan research. ... Etymology: The parasite is named for Prof. Fathy Abdel-Ghaffar,Professor of Parasitology, Cairo Univer-sity, Egypt. REFERENCES ...