ahmed sherif
@arc.sci.eg
Fish diseases/Animal Health Research Institute
Agriculture Research Center
RESEARCH INTERESTS
Fish Diseases
Scopus Publications
Scopus Publications
Ahmed H. Sherif, Lamiaa A. Okasha, Amina S Kassab, Mona E. Abass, and Enas A. Kasem
Springer Science and Business Media LLC
Abstract Background Pollution with heavy metals (HMs) is time- and concentration-dependent. Lead and zinc pollute the aquatic environment, causing severe health issues in aquatic animals. Materials and methods Nile tilapia, the predominant cultured fish in Egypt, were experimentally exposed to 10% of LC50 of lead nitrate (PbNO3) and zinc sulfate (ZnSO4). Samples were collected in three different periods, 4, 6, and 8 weeks, in addition to a trial to treat the experimental fish infected with Aeromonas hydrophila, with an antibiotic (florfenicol). Results Liver enzymes were linearly upsurged in a time-dependent manner in response to HMs exposure. ALT was 92.1 IU/l and AST was 82.53 IU/l after eight weeks. In the eighth week of the HMs exposure, in the hepatic tissue, the levels of glutathione peroxidase (GPx), catalase (CAT), and metallothionein (MT) were increased to 117.8 U/mg prot, 72.2 U/mg prot, and 154.5 U/mg prot, respectively. On exposure to HMs, gene expressions of some cytokines were linearly downregulated in a time-dependent manner compared to the control. After four weeks of exposure to the HMs, the oxidative burst activity (OBA) of immune cells was decreased compared to the control 9.33 and 10.3 cells, respectively. Meanwhile, the serum bactericidal activity (SBA) significantly declined to 18.5% compared to the control 32.6% after eight weeks of exposure. Clinical signs of A. hydrophila infection were exaggerated in polluted fish, with a mortality rate (MR) of 100%. The re-isolation rate of A. hydrophila was decreased in fish treated with florfenicol regardless of the pollution impacts after eight weeks of HMs exposure. Conclusion It could be concluded that the immune suppression and oxidative stress resulting from exposure to HMs are time-dependent. Clinical signs and post-mortem lesions in polluted fish infected with A. hydrophila were prominent. Infected-Nile tilapia had weak responses to florfenicol treatment due to HMs exposure.
Ahmed H. Sherif, Adel E. Toulan, Naglaa El-kalamwi, Enas A. H. Farag, and Abeer E. Mahmoud
Springer Science and Business Media LLC
AbstractMany governments have approved the use of oxytetracycline as an antibiotic additive to food fish, with oxytetracycline now routinely used in many nations. However, oxytetracycline is known to have immunosuppression impacts. We, therefore, evaluated the immunological, antioxidative, and histopathological status of Nile tilapia fed a diet containing silymarin (100 mg/kg fish feed) for 0, 2, 4, 6, and 8 weeks. The protective effects of silymarin against Aeromonas hydrophila (A. hydrophila) infection and oxytetracycline treatment were evaluated. Blood parameters (erythrocyte count, white blood cell count, hemoglobin, and packed cell volume) improved over time in fish fed on dietary silymarin. Serum levels of alanine aminotransferase (ALT) were lower in fish fed on dietary silymarin, whereas serum levels of aspartate transferase (AST)and alkaline phosphatase (ALK) were unchanged. Dietary silymarin affected serum lipid profiles as decreases in serum triglyceride and low-density lipoprotein cholesterol levels and a trend toward lower cholesterol levels, whereas serum high-density lipoprotein cholesterol levels were increased compared to fish fed on the control diet. Dietary silymarin resulted in an increase of serum total protein levels and globulin fractions. Significant and progressive increases in catalase and glutathione peroxidase levels were observed after six weeks of feeding on a dietary silymarin before decreasing to control levels at the end of the experimental period. Fish fed on dietary silymarin, interleukin-1 and fish tumor necrosis factor-alpha were upregulated in hepatic tissues; however, interleukin-10 levels decreased to comparable levels to controls after eight weeks. Fish infected with A. hydrophila displayed septicemia (opaque eye, hemorrhagic ulcers, dentated fins, hepatomegaly, and splenomegaly). Reduced mortality was observed in Nile tilapia infected with A. hydrophila and fed a diet containing silymarin, indicating that silymarin improves fish responses to oxytetracycline with a 37% reduction in mortality.
Ahmed H. Sherif and Amina S. Kassab
Springer Science and Business Media LLC
Abstract Background Aeromonas hydrophila is an opportunistic pathogen. Thus, it has received significant attention mainly in the fish sectors with high production scales. Nile tilapia broodstock confined in the environment of fish hatcheries can be stressed. Hence, they are vulnerable to A. hydrophila. Results Sequencing of the gyr B gene revealed the presence of 18 different A. hydrophila strains (kdy 10,620–10,637), which were deposited in the NCBI under accession numbers ON745861–ON745878. The median lethal doses of the isolates ranged from 2.62 × 104 to 3.02 × 106 CFU/mL. Antibiotic resistant genes, sulfonamide (sul1) and tetracycline (tetA) were found in the eighteen isolates. Approximately 83.3% of A. hydrophila strains were sensitive to ciprofloxacin and florfenicol. Further, eight A. hydrophila strains had high MDR indices at 0.27–0.45. All isolates presented with hemolysin activity. However, only 72.22% of them had proteolytic activity, and only 61.11% could form biofilms. Bacterial isolates harbored different pattern virulence genes, the heat-stable cytotonic enterotoxin (ast), cytotoxic enterotoxin (act), and hemolysin (hly) genes were the most prevalent. Also, a trial to inhibit bacterial growth was conducted using titanium dioxide nanoparticles (TiO2 NPs) with three sizes (13, 32, and 123 nm). If A. hydrophila strains with a high MDR index were tested against TiO2 NPs (20 µg/mL) for 1, 12, and 24 h, those with a small size had a greater bactericidal action than large ones. Bacterial strains were inhibited at different percentages in response to TiO2 NP treatment. Conclusions Nile tilapia broodstock, mortality is associated with different A. hydrophila strains, which harbored virulent and MDR genes. Furthermore, TiO2 NPs had bactericidal activity, thereby resulting in a considerable reduction in bacterial load.
Ahmed H. Sherif, Mariam Elkasef, Magdy E. Mahfouz, and Enas A. Kasem
Elsevier BV
Ahmed H. Sherif, Elsayed A. Eldessouki, Nader M. Sabry, and Nadia G. Ali
Springer Science and Business Media LLC
Ahmed H. Sherif, Mohamed Abdelsalam, Nadia G. Ali, and Karima F. Mahrous
Springer Science and Business Media LLC
Mohamed Abdelsalam, Mamdouh Y. Elgendy, Medhat R. Elfadadny, Sameh Samir Ali, Ahmed H. Sherif, and Said Kamal Abolghait
Springer Science and Business Media LLC
Abstract Egypt is the world’s ninth-largest fish producer with a total production of 1.5 billion tons per year, and farmed fishes comprise almost 79.6% of the total production. Massive mortalities in market-sized farmed fish (freshwater and marine species) were documented all over fish farms in Egypt leading to serious economic losses. The poor biosecurity practices and awareness among smallholder fish farmers accompanied with a long period of temperature fluctuation may predispose farmed fish to be simultaneously coinfected with multiple pathogens. Moribund fishes usually exhibited various septicemic clinical signs and post-mortem lesions indicating that one or more septicemic bacterial pathogens were involved in these outbreak reports. Therefore, rapid and accurate identification of pathogens in the asymptomatic fish population is important for preventing the occurrence of infectious diseases and protecting consumers from seafood-borne illnesses. Molecular techniques provide sensitive, quick, and accurate data for identifying specific pathogens without the need for time-consuming traditional techniques. In addition, the development of cost-effective molecular techniques facilitates their wide implementation in routine clinical diagnostic approaches. Molecular diagnostic methods are useful for simultaneously identifying multiple bacterial pathogens that were challenging to recognize by commercial biochemical techniques. Genetic testing procedures could determine the genetic diversity between closely related strains at the subspecies level. Consequently, these techniques are required for the development of detecting methods for specific strains and for epidemiological investigations in bacterial diseases. This review documented a variety of molecular techniques, including amplification of nucleic acids, polymerase chain reaction (PCR), nested PCR, real-time PCR, multiplex PCR, loop-mediated isothermal amplification (LAMP), DNA microarrays, and nucleotide sequencing assays, that are commonly used to identify fish pathogens.
Ahmed H. Sherif, Elsayed A. Eldessouki, Nader M. Sabry, and Nadia G. Ali
Springer Science and Business Media LLC
Abstract Fish transportation is a regular farming and experimental practice that mainly results in stress conditions that may extend to induce a high mortality rate. In the present experimental simulation, Oreochromis niloticus were transported for 2 h and maintained for another 6 h in transportation containers to assess the effect of tranquilization with tricaine methanesulfonate (MS-222) and/or the addition of iodine on mortality rate and restoring the normal physiological functions. Experimental fish were divided into four groups: group 1 (control) was transported in farm water without MS-222 or iodine, group (2) was transported in farm water supplemented with 40 mg/L of MS-222, fish in group (3) were transported in farm water supplemented with 40 mg/L of MS-222 + 10 ppm iodine, and fish in group (4) were transported in farm water containing 10 ppm iodine. Blood samples were collected for the determination of serum cortisol and glucose, while skin mucus was collected for assaying lysozyme, peroxidase and antibacterial activity; cumulative mortality rate; and food reflexes which were assessed at 0 h, 1 h, 6 h, 48 h, 7 days and 14 days post 2 h transportation. The results indicated that fish tranquilization with MS-222 and/or treatment with iodine mitigated the stress condition associated with transportation and accelerate restoration of the normal physiological and immunological status. So, it was recommended to use the MS-222 as a tranquillizer together with iodine as an antiseptic during transportation of O. niloticus.
Ahmed H. Sherif, Mohamed Abdelsalam, Nadia G. Ali, and Karima F. Mahrous
Springer Science and Business Media LLC
Zinc is an essential element affecting immune responses in aquatic organisms. In the present research, the immunomodulating effect of zinc oxide nanoparticles (ZnO NPs) was studied in Nile tilapia (Oreochromis niloticus). The minimum inhibitory concentration of zinc oxide nanoparticles (ZnO NPs) for Aeromonas hydrophila was estimated at 60 µg/mL. To evaluate the efficacy of ZnO NPs for improving disease resistance against A. hydrophila, three hundred fish were divided into 5 groups. Fish in the group T1 maintained on the control feed, T2 and T3 feed on ZnO at 60 and 30 µg/g, while T4 and T5 received ZnO NPs at 60 and 30 µg/g, respectively for 8 weeks. Immune responses were evaluated by determining the phagocytic activity, serum antibacterial activity, lysozymes, respiratory burst activity, and also gene expression of immunoglobin M-2, tumor necrosis factor-α, interleukin (IL)-1β, heat shock proteins, IL-10, insulin growth factor 1, transforming growth factor-β2, superoxide dismutase enzyme, and catalase enzyme genes. Results indicated that groups that received ZnO NPs have exaggerated immune response and upregulation in the most of expressed immune-related genes. After the feeding trial, all groups were experimentally infected with A. hydrophila, and the mortality rate was monitored. Among all the treated groups, a higher survival rate and disease resistance were observed for fish that received ZnO NPs at 30 and 60 µg/g. The inclusion of ZnO NPs in O. niloticus feed improves both fish immune response and disease resistance against A. hydrophila.
Ahmed H. Sherif and Mohsen A. Zommara
Springer Science and Business Media LLC
AbstractAflatoxin B1 (AFB1) is a plant-origin toxin that could induce oxidative stress in fish. The micromineral selenium (Se) possesses well-documented antioxidant properties. To assess the ameliorative effects of SeNPs (1 mg/kg fish feed) on oxidative stress induced by AFB1 (500 μg/kg fish feed), Nile tilapia (32.2±1.7 g body weight) were distributed randomly and even in six groups for 8-week feeding trial. Live enzymes, AST, ALT, and ALP levels were increased in the serum of fish fed AFB1-contaminated diet, and the addition of SeNPs could restore normal values compared to the control. The gene expression of antioxidant enzymes, superoxide dismutase (SOD) enzyme and catalase (CAT) enzyme, and DNA fragmentation were significantly increased in response to aflatoxin exposure, while dietary SeNPs could mitigate the generated oxidative stress. The innate immunity, serum antibacterial activity (SAA), oxidative burst activity (OBA), phagocytic activities (PA and PI), and gene expression of cytokines (interleukin (IL)-1β, heat shock protein70 (Hsp), and tumor necrosis factor (TNF)-α) revealed a status of immunosuppression in Nile tilapia fed on AFB1-contaminated diet. These findings showed that fish became more vulnerable to Streptococcus agalactiae infection with a high mortality rate while dietary SeNPs provided a high relative protection level (RPL). From the obtained findings, SeNPs could mitigate the oxidative stress induced by feeding the AFB1 diet and could boost the immunity of stressed Nile tilapia.
Walaa S. Tawfeek, Amina S. Kassab, Lamiaa A. Okasha, Mohamed Abdelsalam, and Ahmed H. Sherif
Springer Science and Business Media LLC
AbstractTo investigate the presence of Pseudomonas anguilliseptica, one hundred specimens of sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) were collected alongside water samples during episodes of widespread fish mortality in marine fish farms located in the northern region of Egypt. This study documented the clinical and postmortem manifestations observed in moribund sea bream and sea bass, thus providing evidence for the occurrence of a septicemic-hemorrhagic bacterial disease. Fourteen strains of P. anguilliseptica were isolated and characterized from both sea bream and sea bass specimens. The conventional bacteriology methods were employed to retrieve the causative bacterial agent and subsequently evaluate its phenotypic traits. Moreover, sequencing of the 16 S rRNA was conducted to characterize the identified microorganism. Furthermore, multilocus sequence analysis (MLSA) was employed to confirm the identity of P. anguilliseptica and elucidate the phylogenetic interrelationship among various strains. Regardless of their source or the fish species from which the strains were obtained, these isolates showed a high level of phenotypic homogeneity. MLSA displayed a genetic homogeneity among isolates despite their different geographic origins. Antibiogram revealed the sensitivity of some P. anguilliseptica strains for antibiotics (florfenicol, trimethoprim, sulfamethoxazole, cefotaxime, and ciprofloxacin). Isolated strains were harboring some antibiotic-resistant genes, with the most prevalent being tetA gene, followed by ermB gene. Water physico-chemical parameters (low temperature and salinity fluctuation) were convenient for bacterial growth. In addition, P. anguilliseptica strains could resist several antibiotics and harbored antibiotic-resistant genes, resulting in difficulties in fish treatment.
Ahmed H. Sherif, Enas A. H. Farag, and Abeer E. Mahmoud
Springer Science and Business Media LLC
AbstractIn Egypt, the temperature of the water fluctuates drastically, reaching a daytime high of 25 °C and a nighttime low of 15 °C, respectively, in the spring and the fall. To understand the mechanism behind fish kill in fish farms, an indoor experiment was conducted wherein 240 Nile tilapia weighing 24 ± 2.5 g were stocked in 12 glass aquaria (20 fish/aquarium). Water temperature was regulated throughout the day at 27 ± 1.5 °C for 12 h from 8:00 a.m. to 8:00 p.m. and at 18 ± 1.5 °C for the remaining 12 h. Fish samples (mucus and tissues) were collected four times with a week interval. Proinflammatory tumor necrosis factor-α and interleukin (IL)-1β were decreased during the 4 weeks, while anti-inflammatory IL-10 was highly upregulated during the first week and then decreased compared to the control. Heat shock protein-70 was significantly raised, but IL-8 was unaffected. The gene expressions of antioxidant enzymes catalase and glutathione peroxidase were markedly elevated in the first week and then decreased linearly until they no longer differed from the control group. Mucus lysozyme significantly decreased in weeks 1 and 2 and then began to increase in weeks 3 and 4. Every week, Aeromonas hydrophila infection resulted in clinical signs that were delayed by over 2 days compared to the control group. The mortality rate increased from 35 to 40%, and bacteria were isolated at a rate of 61.54 to 75% from the surviving fish, compared to a rate of 41.67% in the control group. Fluctuations in water temperature suppress the immunity of Nile tilapia, making them vulnerable to bacterial infection.
Elsayed A. Eldessouki et al.
Egypts Presidential Specialized Council for Education and Scientific Research
Marwa M. Attia, Mohamed Abdelsalam, Mamdouh Y. Elgendy, and Ahmed H. Sherif
Elsevier BV
Nadia Gabr Ali, Tamer El-Sayed Ali, Maysa Fathy Kamel, Reda Saleh, Ahmed H. Sherif, and Ibrahim Mohamed Aboyadak
Elsevier BV
Mamdouh Y. Elgendy, Ahmed H. Sherif, Amany M. Kenawy, and Mohamed Abdelsalam
Elsevier BV
Ahmed H. Sherif, Riad H. Khalil, Mahmoud Tanekhy, Nader M. Sabry, Mohammed A. Harfoush, and Mahmoud A. Elnagar
Wiley
Ahmed H. Sherif et al.
Egypts Presidential Specialized Council for Education and Scientific Research
1. Department of Fish Diseases, Animal Health Research Institute, ARC, Kafrelsheikh, Egypt 2. Department of Fish Diseases, Animal Health Research Institute, ARC, Dokki, 12619, Egypt 3. Pathology Unit, Animal Health Research Institute, ARC, Kafrelsheikh, 12619, Egypt 4. Immunology Unit, Animal Health Research Institute, ARC, Kafrelsheikh, 12619, Egypt 5. Fish Diseases Unit, Animal Health Research Institute, ARC, Assiut, 12619, Egypt * Corresponding Author:: ahsherif77@yahoo.com __________________________________________________________________________
Ahmed H. Sherif, Abdelbary Prince, Ahmed Adel Seida, Mahmoud Saad Sharaf, Elsayed A. Eldessouki, and Mohammed A. Harfoush
Wiley
Marwa A. Ebied et al.
Egypts Presidential Specialized Council for Education and Scientific Research
1. Bacteriology Department, Animal Health Research Institute AHRI, Agriculture Research Centre ARC, Kafrelsheikh, 12619 Egypt 2. Department of Microbiology, Faculty of Veterinary Medicine, Alexandria University, Alexandria, 22758 Egypt 3. Fish Diseases Department, Animal Health Research Institute AHRI, Agriculture Research Centre ARC, Kafrelsheikh, 12619 Egypt Corresponding Author: ahsherif77@yahoo.com, ______________________________________________________________________________________
Soad S. Abd El-Halim Salama et al.
Egypts Presidential Specialized Council for Education and Scientific Research
Olfat A. Mahdy et al.
Egypts Presidential Specialized Council for Education and Scientific Research
1 Department of Parasitology, Faculty of Veterinary Medicine, Cairo University, 12211, Egypt 2 Fish Diseases Department, Animal Health Research Institute AHRI, Agriculture, Research Centre ARC, Kafrelsheikh,12619, Egypt 3 Fish diseases lab., National Institute of Oceanography and Fishery (NIOF), Egypt. 4 Department of Aquatic Animal Medicine and Management; Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt 5 Department of Biochemistry, Faculty of Veterinary Medicine, Cairo University, 12211 Giza, Egypt. 6 Scientific Research Department, Armed Forces College of Medicine, Cairo, Egypt 7 Department of Microbiology and Immunology, Faculty of Veterinary Medicine, Cairo University, 12211, Egypt Corresponding Author: ahsherif77@yahoo.com ______________________________________________________________________________________
Ahmed H. Sherif, Mohamed El‐Sayed El‐Sharawy, Salma I. El‐Samannoudy, Ahmed Seida, Nader M. Sabry, Mohamed Eldawoudy, Mohamed Abdelsalam, and Nehal A. Younis
Wiley