Export 48 results:
Sort by: Author Title Type [ Year  (Desc)]
Elgohary, I., A. E. Eissa, N. G. Fadel, J. I. A. Elatief, and M. A. Mahmoud, "Bacteriological, molecular, and pathological studies on the Gram-positive bacteria Aerococcus viridans and Enterococcus faecalis and their effects on Oreochromis niloticus in Egyptian fish farms", Aquaculture Research, vol. 52, issue 5, pp. 2220-2232, 2021.
Ali, K. M., E. A. Hassan, M. M. Abuowarda, M. A. Mahmoud, and F. A. Torad, "Bilateral panophthalmia as a late sequel of leishmaniasis in dogs", Pakistan Veterinary Journal, vol. 41, issue 1, pp. 13-18, 2021.
Eissa, A. E., M. Abdelsalam, M. A. Mahmoud, N. A. Younis, A. A. A. Mhara, and R. E. A. Zlit, "Cutaneous fibropapilloma in Egyptian-farmed gilthead seabream (Sparus aurata; Linnaeus, 1758)", Aquaculture International , vol. 28, pp. 2081–2091, 2020.
Mahrous, K. F., D. M. Mabrouk, M. M. Aboelenin, H. A. A. M. El-Kader, A. Y. Gaafar, A. M. Younes, M. A. Mahmoud, W. K. B. Khalil, and M. S. Hassanane, "Molecular characterization and immunohistochemical localization of tilapia piscidin 3 in response to Aeromonas hydrophila infection in Nile tilapia", Journal of Peptide Science, vol. 26, issue e3280, pp. 1-11, 2020.
Mahdy, O. A., M. A. Mahmoud, and M. Abdelsalam, "Morphological characterization and histopathological alterations of homologs Heterophyid metacercarial coinfection in farmed mullets and experimental infected pigeons", Aquaculture International , vol. 28, pp. 2491–2504, 2020.
Elgohary, I., J. A. I. Elatief, N. G. Fadel, A. E. Eissa, and M. A. Mahmoud, "Pathological, bacteriological and seasonal prevalence of Aeromonas hydrophila, vibrio vulnificus, Proteus vulgaris and Pseudomonas aeruginosa; infecting Oreochromis niloticus in some Egyptian fish farms", Egyptian Journal of Aquatic Biology & Fisheries, vol. 24, issue 5, pp. 467 – 482, 2020.
Mahrous, K. F., M. M. Aboelenin, H. A. A. M. El-Kader, D. M. Mabrouk, A. Y. Gaafar, A. M. Younes, M. A. Mahmoud, W. K. B. Khalil, and M. S. Hassanane, "Piscidin 4: Genetic expression and comparative immunolocalization in Nile tilapia (Oreochromis niloticus) following challenge using different local bacterial strains", Developmental and Comparative Immunology , vol. 112, issue 103777, 2020.
Mahmoud, M. A., H. A. Mansour, M. Abdelsalam, H. O. AbuBakr, S. H. Aljuaydi, and M.Afify, "Evaluation of electrofishing adopted by Egyptian fish farmers", Aquaculture , vol. 498, pp. 380–387, 2019.
Mahmoud, M. A., A. A. H. El-Rahim, K. F. Mahrous, M. Abdelsalam, N. A. Abu-Aita4, and M. Afify, "The impact of several hydraulic fracking chemicals on Nile tilapia and evaluation of the protective effects of Spirulina platensis", Environmental Science and Pollution Research, vol. 26, pp. 19453–19467, 2019.
Osman, A. H., E. M. M. F. Hala, A. M. Zakia, A. M. Mahmoud, M. H. Mohamed, A. M. Khattab, and Z. M. A. Ewiss, "RABBIT'S HEALTH AND ENVIRONMENTAL IMPACTS OF EXPLOITATION TREATED BIODEGRADABLE POLLUTION WATER BY JOHKASOU SYSTEM", Taiwan Veterinary Journal, vol. 44, issue 1, pp. 1-8, 2018.
NaveenKumar, S., M. A. Hassan, M. A. Mahmoud, and A. Al-Ansari, "Betanodavirus infection in reared marine fishes along the Arabian Gulf", Aquacult Int, vol. 25, pp. 1543–1554, 2017.
Hassan, M. A., E. A. Noureldin, M. A. Mahmoud, and N. A. Fita, "Molecular identification and epizootiology of Aeromonas veronii infection among farmed Oreochromis niloticus in Eastern Province, KSA", Egyptian Journal of Aquatic Research, vol. 43, pp. 161-167, 2017.
Mahmoud, M. A., M. Abdelsalam, and O. A. Mahdy, "Infectious bacterial pathogens, parasites and pathological correlations * of sewage pollution as an important threat to farmed fishes in Egypt", Environmental Pollution , vol. 219, issue 2016, pp. 939-948, 2016.
Karima, M. F., H. M. Aziza, R. A. Hasnaa, and M. A. Mahmoud, "Inhibition of cadmium- induced genotoxicity and histopathological changes in Nile tilapia fish by Egyptian and Tunisian montmorillonite clay", Ecotoxicology and Environmental Safety, vol. 119, issue 2015, pp. 140- 147, 2015.
Hassan., M. A., W. S. Soliman., M. A. Mahmoud., and M. I. Sami Shabeeb Al-Shabeeb, "Prevalence of Bacterial Infections among Cage-Cultured Marine Fishes at the Eastern Province of Saudi Arabia.", Research Journal of Pharmaceutical, Biological and Chemical Sciences , vol. 6, issue 4, pp. 1112-1126, 2015.
Nisreen, E. M., A. M. Mahmoud, and M. M. Fahmy, "Parasitological and Comparative Pathological Studies on Monogenean Infestation of Cultured Sea Bream ( Sparus aurata , Spariidae) in Egypt", Oceanography, vol. 2, issue 4, pp. 129, 2014.
Hassan, M. A., A. M. Hussien, and A. M. Mahmoud, "Studies on Dermocystidiosis (Yellow Muscle Disease) among Some Marine Fishes of Arabian Gulf and Red Sea Coast, Jeddah, Saudi Arabia", Middle-East Journal of Scientific Research, vol. 22 , issue 4, pp. 478-487, 2014.
Mahmoud, A. M., and A. N. Z. Gindy, "Treatment of Monogenic Parasites in Imported Hybrid Red Tilapia Fries ( Oreochromis SPP) In the Sultanate of Oman", Agricultural and Marine Sciences. , vol. 16, pp. 35-40. , 2011. Abstract

In February, 2008, 12000 fries of monosex red tilapia hybrid (Oreochromis SPP) of 0.2 g and 12000 fries of monosex Nile tilapia (Oreochromis niloticus) of 0.5 g were imported from a hatchery in South East Asia and stocked in concrete raceways at an agriculture farm in the Barka Region about 80 km from Muscat. Three days after stocking, mortality problems were observed. The preliminary inspection revealed abnormal flashing movements of the fish with body scratching against the walls. Faint grayish white discoloration was observed externally on the skin and fins with focal hemorrhagic areas. Examination of skin and gill biopsies demonstrated the presence of a large number of small sized monogenea parasitic worms attacking the tissue of these body regions. Histopathological observations revealed tissue reactions against the parasites and demonstrated a severe dermatitis of the skin, lamellar oedema and hyperplasia of the branchial tissue. A concomitant treatment regime using mebendazole, salt and formalin was practiced for three successive days and repeated three times every week together with parallel management procedures to enhance water quality during treatment. After treatment, a reduction of mortality was noticed within three days and completely ceased after one week at which time biopsy examinations revealed the absence of any parasitic agents. There were no deaths reported among the Nile tilapia, which were raised on the same farm.

Moustafa, M., M. A. Laila, M. A. Mahmoud, and -gendyM. E. Y. W. S. Soliman, "Bacterial Infections Affecting Marine Fishes in Egypt", Journal of American Science , , , vol. vol. 6, no.11, pp. 603-612, 2010. Abstract

Some fish species are suffering from continuous depletion due to devastating environmental changes at their native aquatic environment. Qarun Lake and Suez Gulf are among the most vulnerable areas. Thus, representative fish samples from those areas were inspected for the presence of any fish pathogenic bacteria. The inspected samples included six different species; Epinephelus tuvina, Siganus rivulatus, and Dedlechilus labiosus native to Suez Gulf at Suez governorate; Tilapia zilli, Mugil capito and Solea vulgaris native to Qarun Lake at El- Fayoum governorate. A total of 600 samples were examined throughout the different year seasons. Gram positive and negative fish pathogenic bacteria were isolated from a total of 245 fish sample. Among those samples, the following bacteria were retrieved in the following percentages respectively, 17.55% (V. anguillarum), 16.73% (V. alginolyticus), 15.51% (P. piscicida), 15.91% (Ps. fluorescens), 13.46% (S. fecalis), 11.02% (A. hydrophila), 6.12% (A. sobria) and 3.67% were infected with Staph. aureus. The Siganus rivulatus was the highest infected fish species with a prevalence of 8.33%, while Mugil capito was the lowest infected species (5.67 %). The highest total prevalence of bacterial infection was recorded in summer season (40.81%) while the lowest was recorded in winter (15.91%). The aforementioned bacterial isolates were successfully re-isolated from experimentally infected fish. The retrieved isolates were matched against standard isolates as well as confirmed to be positive using semi- automated (API 20 E) and conventional biochemical tests.

Mohamed, A. H., M.A.Hassan, and A. M. Mahmoud, "Infestation of Some Marine Fish Species with Red Worm Philometra", Arab Gulf Journal of Scientific Research, vol. 28, issue 3, pp. 137- 146 , 2010.

The present study was carried out to evaluate the protective effect of vitamin C (vit. C) against genotoxic and pathological changes induced by arsenic (As), zinc (Zn) and their mixture in Oreochromis niloticus. Fish of almost the same weight and size were divided into 13 groups (6 groups were exposed for 3 weeks and the other 6 groups were exposed to the same treatment but for 6 weeks) beside the control group (10 fish/group). The 1st group was served as control, the 2nd group was exposed to 2.9 mg/L of As in the form of sodium salt in water for 3 weeks. The 3rd group was exposed to As plus vit. C (10mg/kg diet equivalent to 30 gm/kg bw). The 4th group was exposed to 3mg/L of Zn in the form of zinc sulfate. The 5th group was exposed to Zn and vit. C. The 6th group was exposed to both As and Zn. The 7th group was exposed to As, Zn and vit. C. Five samples from each group were sacrificed at 3rd and 6th week of the experiment, respectively, and subjected to cytogenetical and histopathological examination. Gross lesions were recorded along the time of exposure. The results revealed genotoxicity in O.niloticus exposed to As and/ or Zn for 6 weeks. There was a significant increase of micronuclei (Mn) in all As and/or Zn exposed fish groups, compared to the control, while the treatment with vit. C significantly decreased the frequency of Mn in all As and/or Zn exposed groups. The histopathological examination revealed severe pathological lesions in gills, skin, muscles and liver in case of As toxicity, while in case of Zn toxicity, the changes were common in liver and spleen and other internal organs. In both cases, vit. C protects the tissue against such toxicity. In conclusion, this study proved that As and Zn had genotoxic effect on O.niloticus and that appear in the significant increase in the frequency of Mn induced by these metals, whereas the treatment with vit. C reduced that genotoxic effect especially with long term treatment. In addition, the histopathological lesions were recorded in As and/or Zn exposed groups for 3 w, whereas the alterations were more clear in 6 w exposed groups. Minor or no lesions were noticed in all vit. C treated groups.

Mahmoud, M. A., S. M. Aly, A. S. Diab, and G. John, "The role of ornamental goldfish Carassius auratus in transfer of some viruses and ectoparasites to cultured fish in Egypt: comparative ultrapathological studies.", African Journal of Aquatic Science , vol. 34, issue 2, pp. 111–121, 2009.
Mahmoud, A. M., and A. I. Tanios, " Pathogenicity of Aeromonas hydrophila in chickens", Egyt. J. of Comp. Path. & Clinical Path., , vol. 21, no. 3 , pp. 88-110, 2008. Abstract

.Seventeen isolates of Aeromonas hydrophila were isolated from 250 commercial broiler chicks with an incidence of 6.8 %. Most A. hydrophila isolates (88.24 %) were positive for exotoxin assay and congo red binding test, while 52.94 % were positive for crystal violet binding activity. Most strains of A. hydrophila were sensitive to chloramphenicol, ciprofloxacin and norfloxacin followed by gentamicin and neomycin while nalidixic acid, tetracycline, streptomycin and trimethoprim sulphamethoxazole had moderate effect. On the other hand, all A. hydrophila strains were resistant to amoxicillin, cephalothin, erythromycin and penicillin G. All chicks infected with 1.5 X 109 organisms via subcutaneous and yolk sac were dead within 24 h. A. hydrophila was isolated from most organs. The lesions observed included congestion in the internal organs and few cases showed hepatic and muscular petechiae. Histopathological examination of experimentally infected chicks revealed severe necrosis in hepatic, splenic and muscular tissue in the two days old chicks. The ultrastructural study of this group showed presence of the bacilli inside the hepatocytes and macrophages with marked cellular changes. An attempt was made to determine a correlation between level of exposure and mortality. It was found that the mortality rate was relatively high (52.5 %) than in lower dose (35 %). A. hydrophila was isolated from most organs examined. Marked degenerative and necrobiotic changes in both hepatic and splenic tissue and characteristic muscular lesions manifested by muscular hemorrhage, degeneration, oedema and myositis in low dose treatment group. In the group injected with high dose, the lesions were more severe and characterized by diffuse areas of necrosis in hepatic tissue, thrombus formation in the blood vessels together with large number of bacterial colonies and bacilli in the hepatic tissue. Marked muscular necrosis and myophagia were also noticed. The ultrastructural study using transmission electron microscope for this group showed heterocells and hepatocytes contain bacilli. In other cases, the bacilli were present in the phagosomes of phagocytic cells in the splenic tissue. Cytopathological lysis was common evidence in the examined cells.

Mahmoud, A. M., A. E. R. H. Abeer, and A. - A. A. Nashwa, " Effect Of Confinement Stress On Behaviour, Performance, Clinicopathological And Histopathological Alterations Of Nile Tilapia Challenged With Aeromonas hydrophila With Regard To The Blue Light As Stress Inhibitor ", Veterinary Medical Journal, vol. , 55, no.3 , pp. 687-717, 2007. Abstract

The present study was carried out to assess the effects of blue light as antistressor and its effect on susceptibility of Nile tilapia (Oreochromis niloticus) to Aeromonas hydrophila (A. hydrophila) infection. A total number of (120) O. niloticus was divided into 3 experimental groups (40 fish / group). Group 1 (G1), was exposed to normal day light and considered as control group. Group 2 (G2), was exposed to blue light. Group 3 (G3), was exposed to white light (fluorescent illumination). After 15 days of light exposure, fish in groups 2 and 3 were confined into small area and then challenged with A. hydrophila infection. The obtained data revealed that during exposure to blue light, the fish of (G2) recorded significant lower proportion in behavioural parameters including factors of fright behaviour "creeping, oblique plan position and air-gulping" than those of﴾G3﴿. On the other hand, (G2) showed lower behaviour alterations for fright behaviour during confinement and infection than those of﴾G3﴿. Contrarily, it also had significantly higher proportions of aggressive behaviour during exposure to light, confinement and infection than﴾ G3﴿. SO blue light improved behaviour and fish become more comfortable in (G2) than (G3). Moreover, fish of (G2) showed higher significant growth performance during exposure to blue light and little reduction in growth performance during exposure to both confinement and infection than those of (G3). The clinicopathological studies revealed significant increase in the stress response indicators after exposure to confinement stress in (G.3). Marked elevation in the serum cortisol, glucose levels and significant leukocytosis associated with heterophilia and lymphopenia was observed in group 3 (G3). On the other hand, non significant changes were observed in the measured stress parameters in group (G 2) which exposed to the blue light. Exposure of stressed fish to A. hydrophila infection induced significant leukocytosis with heterophilia, monocytosis and lymphopenia in both (G2&G3). Analysis of serum biochemical constituents showed significant elevation in ALT, AST, BUN, creatinine and glucose while significant reduction in the total proteins, albumen and globulin was achieved. These changes were more pronounced and early detected in A. hydrophila infected stressed fish exposed to white light compared to those exposed to blue light From pathological point of view, fish group which exposed to blue light and infection revealed early positive immune response "activation of melanomacrophage center of spleen" but with time dependent adverse pathological lesion. The lesions were noticed in spleen and gills after 2 weeks. Regeneration of the most observed lesions were detected after 4 weeks. On the other hand, the fish group exposed to white light and infection showed more advanced lesions including diffuse necrosis in hepatic tissue with additional changes in the kidneys. So, the blue light has a protective effect aganist stress in Nile tilapia.