Research Publications

The present work aims to evaluate the impact of Lake Manzala development, started in 2017, on lake water quality and biomarkers of Lake Oreochromis niloticus and Biomphalaria alexandrina samples from Dakahlia and Port Said during 2021 and compare it with the results of a series of studies concerning the same criteria in Lake Manzala during 2015. Results showed a remarkable increase in water EC, indicating a higher water exchange with the sea, a significant decrease in Pb, Cd, Cu, and Zn levels in water samples, and a remarkable decline in Cd and Pb bioaccumulation in all fish and snail samples. Macroinvertebrate samples showed higher taxa richness than in 2015, indicating biologically improved lake water quality. Results showed no trematode transmission, while there were natural infections in B. alexandrina snails during 2015. Biochemically, liver enzymes and hematological criteria in fish and snail samples during 2021 showed levels nearer to control at Port Said, indicating a less stressed liver and more healthy specimens than in 2015. Histopathological examination of fish organs (except spleen) and snail tissues pointed to their improved tissue architecture in Port Said than that of Dakahlia (2021). However, the 2021 samples were better than those of 2015. The immunohistochemical study showed higher expression of IL-6 in Dakahlia samples than the other samples, denoting higher tissue inflammation and humoral immune response. So, all the examined criteria indicated that Manzala Lake is positively impacted by the developmental and purification process, especially in Port Said. © 2023 Elsevier Ltd

The present work aimed to study the water quality of six Delta Egyptian governorates using ArcGIS maps. Compared to winter, water temperature was higher during summer in all selected governorates. Dissolved oxygen (D.O.) was higher than in summer during winter in all selected governorates. The maximum atmospheric temperature (Tmax) was higher in current work than that recorded throughout the past ten years in Damietta and Beheria governorates during spring, while it was high at Kafr El-Sheikh in autumn and summer. Tmax was directly proportional to the observed water temperature and inversely proportional to D.O. Water temperature showed negative correlations with all physicochemical parameters. Cd levels were relatively high in winter in all examined governorates. Pb level raised at Gharbia, Dakahila, and Monfia in winter and spring. Cu and Fe levels were moderately high during all seasons, while Zn levels were high and moderate in Kafr El-Seikh and Damietta in spring. The spatial distribution gave a visual picture of the main parameters affecting the water quality in the examined governorates. © 2023, Egyptian Society for the Development of Fisheries and Human Health. All rights reserved.

Contamination of water and sediment with pyrethroids and triazoles residues can affect fungal diversity, and hence the aquatic system functioning. The aim of the present study is to investigate the effect of water and sediment contamination with pyrethroids and triazoles on fungal diversity. Water and sediment samples were seasonally collected along 2019 from water bodies representing Gharbeya and Qualubeya governorates. Concentrations of pyrethroids and triazoles were determined, and fungal species in water and sediment samples were molecularly identified. The results indicated that temperature and pH varied according to the season. Permethrin, deltamethrin, lambda-cyhalothrin and esfenvalerate showed the highest pyrethroids concentrations, whereas tetraconazole, tebuconazole and difenconazole were of the highest triazoles concentrations. Aspergillus niger was one of the most frequent species, in addition to Trichoderma capillare, Fusarium oxysporum, Penicillium commune and Penicillium polonicum. Principal component analysis indicated a positive correlation between temperature and different Aspergillus spp., and between pH and each of pyrethroids and triazoles. Moreover, a negative correlation was observed between triazoles and Trichoderma asperellum, Penicillium griseofulvum and Aspergillus fumigatus. In conclusion, contamination of water with pesticides affected fungal diversity. This disturbance in fungal assemblages might result in a reduction of some key organisms, or an increase and emergence of new pathogens. © 2023 Taylor & Francis Group, LLC.

In the past three decades, a significant progress has been made in the prevention and treatment of gastric ulcers. The incidence of the disease has decreased, but gastric ulcer is still a medical problem. Currently, the available drugs for gastric ulcer treatment have many side effects; therefore, searching for new and safe therapeutic agents is mandatory. The present study aims to investigate the gastroprotective potential of Cornu aspersum (C. aspersum) mucin against gastric ulcers, and the mechanisms related to oxidative stress and inflammation. C. aspersum mucin was collected from 50 snails. The characteristics of C. aspersum mucin (chemical and microbiological) were evaluated. Mice were pretreated with famotidine and C. aspersum mucin (7.5 and 15 ml/kg b.w.) for 5 days, and then gastric ulcers were induced by indomethacin. Macroscopic examination, biochemical estimations, and Quantitative real-time PCR were carried out. Also, histopathological and immunohistopathological examinations were evaluated. We found that the high dose of the mucin significantly decreased the gastric mucosal malondialdehyde (MDA) and nitric oxide (NO) contents as well as interleukin 1β (IL-1β) and nuclear factor kappa β (NF-ҡB) expression, and inducible nitric oxide synthase (iNOS) immunostaining. It also increased the gastric mucosal GSH and catalase contents as well as hemoxygenase-1 (HO-1) and nuclear factor-erythroid 2-related factor 2 (Nrf2) expressions with regressions in gastric mucosal lesions. In conclusion, C. aspersum mucin could be a potential therapeutic candidate to protect against gastric ulceration. © 2023 The Authors

Introduction: Endophytic fungi are good sources of bioactive compounds that are exclusive to their hosts. Eichhornia crassipes plant produces different bioactive compounds. The aim of the present study is to isolate and identify endophytic fungi that reside in Eichhornia crassipes tissues, and to evaluate the biological activities of their extracts. Materials and Methods: Endophytic fungal spp. were isolated from leaves and petioles of Eichhornia crassipes, identified and then extracted. The ethyl acetate extracts were tested against bacteria, fungi, hepatitis B virus and Schistosoma mansoni cercariae. The chemical composition of these extracts was determined by Gas chromatography-mass spectrometry (GC-MS/MS) analysis. Results: We found that four fungal spp. were dominant in Eichhornia crassipes; they were molecularly identified as Aspergillus flavus OM758315, Aspergillus fumigatus OM688980, Aspergillus welwitschiae OM758326 and Corynascus sepedonium OM688206, with A. flavus as the most frequent. The ethyl acetate extract of the four fungal spp. showed pronounced antimicrobial effects, whereas the highest antiviral effect on hepatitis B virus was that of A. flavus followed by A. fumigatus extracts. All the tested extracts were cercaricidal to Schistosoma mansoni cercariae, where A. flavus was the most effective. GC-MS/MS analysis indicated the presence of various bioactive compounds. Conclusions: Aspergillus flavus, Aspergillus fumigatus, Aspergillus welwitschiae and Corynascus sepedonium as endophytes of Eichhornia crassipes showed promising antimicrobial, antiviral and cercaricidal properties. © 2023 The Author(s).

Continuous field studies on the abundance and distribution of freshwater snails and cercarial populations are important for schistosomiasis control programs. In the present work, snail surveys and cercariometry were conducted for four successive seasons at 12 sites on the Nile River banks in the area of Greater Cairo to identify potential transmission foci for schistosomiasis. In addition, water physicochemical parameters were recorded. The results showed that the electrical conductivity, total dissolved solids, dissolved oxygen, and pH were within the permissible levels, except that the water temperature increased, especially in the spring season. Malacological surveys identified 10 native snail species at the studied sites of the Nile River, namely Bulinus truncatus, Biomphalaria alexandrina, Lymnaea natalensis, Lanistes carinatus, Cleopatra bulimoides, Melanoides tuberculata, Helisoma duryi, Bellamya unicolor, Physa acuta, Thedoxus niloticus, and one invasive snail species, Thiara scabra. The calculated diversity index indicated that the structure of snails’ habitats was poor, while Evenness index indicated that the individuals were not distributed equally. Natural infection results identified no schistosome cercariae in B. truncatus and B. alexandrina. However, the cercariometry recovered Schistosoma cercariae in all the surveyed sites during all seasons with variable distribution. The preceding data suggest that there are still some active transmission foci for schistosomiasis infection in the Nile River. Moreover, the present finding highlights the importance of cercariomety as a complementary approach to snail samplings for identifying the transmission foci for schistosomiasis. © 2022, Indian Society for Parasitology.

Artificial light near rivers and lakes can have a substantial impact on aquatic species, especially freshwater snails, in terms of behavioral and physiological parameters. The extent to which this alternation may occur is unknown, particularly if this snail serves as an intermediate host for the parasite Schistosoma mansoni. As a result, the goal of this study is to see how light from high-pressure sodium (HPS) and light-emitting diode (LED) lights interact with Schistosoma mansoni infection in Bimophalaria alexandrina snails. The survival rate of infected snails and the mean number of cercariae/snails exposed to HPS was significantly higher than those exposed to LED. The investigation revealed that infected snails were more active and traveled longer distances at a higher speed post the 4th week of the exposure to LED light. Results of biochemical parameters showed a highly significant elevation in malondialdehyde (MDA) activity post-exposure to LED, while a highly significant increase in total antioxidant capacity (TAC) was recorded after exposure to HSP. The histopathological examination of infected snails exposed to LED showed highly affected digestive tissue, degenerated sporocysts, and incomplete mature cercariae, while the infected snails exposed to HPS showed well-developed sporocysts and mature cercariae with differentiated heads and tails. Snails exposed to LED showed a highly significant decrease in serotonin levels compared to those exposed to HPS. Melatonin levels recorded significant differences between the exposed groups to LED and HPS. The current study recommends using artificial LED lighting around freshwater canals instead of HPS lighting, which could limit the transmission of schistosomes. © 2022, Egyptian Society for the Development of Fisheries and Human Health. All rights reserved.

Searching for molluscicidal agents of biological origin is mandatory to avoid the drawbacks of using chemical molluscicides. Algae are good candidates as sources of compounds with molluscicidal properties, especially if they are combined with modern techniques such as nanotechnology. This study aimed to evaluate the molluscicidal activity of two algal extracts and their biosynthesized zinc oxide nanoparticles (ZnONPs) on Biomphalaria alexandrina snails. The results indicated that the lowest LC50 was that of Spirulina platensis extract followed by Scenedesmus obliquus extract. Subchronic experiments were conducted for 2 weeks to indicate the effect of LCo of S. obliquus and S. platensis extracts, and 1/4 LCo of ZnONPs synthesized by S. obliquus and that synthesized by S. platensis. Histopathological alterations were observed in the digestive and hermaphrodite glands of treated snails. Also, random amplified polymorphic DNA-polymerase chain reaction indicated genotoxic effects in the DNA of treated snails, as 1/4 LCo of ZnONPs synthesized by S. obliquus was the most effective treatment. The toxicity assay using Artemia salina indicated that the effective concentrations on B. alexandrina snails were safe on other non-target organisms. © 2022 John Wiley & Sons Ltd.

The present study aims to evaluate the potential effects of cyanobacteria on water quality parameters and Oreochromis niloticus in the fish ponds at Al-Abbassa Fish Hatchery, Sharkia Governorate, Egypt. The study identified five cyanobacterial genera: namely, Anabaena, Gleotrichia, Lyngbya, Oscillatoria and Phormidium. Oscillatoria sp. was the dominant genus in the selected fish ponds. Physico-chemical parameters of water samples showed significant variations during the four seasons. Anabaena sp. extract had the most toxic effect on the survival rate of O. niloticus after 72 h of exposure. Biochemical parameters of collected O. niloticus fish significantly increased compared to the control group. We concluded that the detected cyanobacterial genera in the fish ponds affected water quality and O. niloticus fish. © 2022 Informa UK Limited, trading as Taylor & Francis Group.

Schistosomiasis still affects a lot of people in many developing countries. Reducing the disease dissemination has been the target of various studies. As methyl gallate has antioxidant properties, it is assumed that it can be a good candidate for stimulating the immune response of snails. So, the aim of this work is to investigate the potential of using methyl gallate as an immunostimulant to Biomphalaria alexandrina snails in order to prevent the development of invading miracidia into infective cercariae. The infected snails were exposed to three concentrations of methyl gallate for two periods: 24 and 72 h. The results indicated that the most effective concentration was the lowest one: 125 mg/L of methyl gallate for 72 h, as it reduced both infection rate and mean number of shed cercariae. Also, it increased the total number of snails’ hemocytes in hemolymph, which were observed in head-foot region and digestive gland of treated snails surrounding degenerated sporocysts and cercariae. In addition, hydrogen peroxide showed its highest content in tissues of snails exposed to 125 mg/L of methyl gallate for 72 h. In conclusion, methyl gallate can be considered as one of the most promising immunostimulants of B. alexandrina snails against infection with Schistosoma mansoni. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.