A feeding trial was performed to evaluate the efficacy of Dietary Nucleotides (Nucleoforce™) on Growth performance, haematological, biochemical, Immunological indices and disease resistance of Pangasianodon hypophthalmus fish to Pseudomonas aeruginosa. Dietary nucleotides were incorporated in the diet at different concentrations; group I control, group II 250 g/ ton diet and group III 500 g/ ton diet for 8 weeks. At the end of the feeding trial, weight gain, and specific growth rate (SGR) were recorded. Results showed that there was a significant increase in fish groups received diet supplemented with nucleotides in comparison with the control group. Haematogram indices showed a significant elevation in RBCs count, HB value, WBCs, and leukocytic count. Biochemically, High superoxide dismutase (SOD) activity, total protein and globulin levels were recorded in fish fed on 500g/t nucleotide (NT). Immunologically, Lymphocytic proliferation activity, Nitric oxide concentration and Serum lysozyme activity were continuously increased in 250g/t and the 500g/t NT treatment groups along feeding duration. At the end of 8th week, the experimentally reared fish were challenged intraperitoneally with virulent strain of Pseudomonas aeruginosa (0.2 ml of 3× 107 CFU) and the cumulative mortalities were recorded to be lower in nucleotide supplemented groups compared to the control group. In conclusion, the supplementation of fish diet with nucleotides in concentration of 500g/t nucleotide can improve the general health status of P. hypophthalmus via increasing the disease resistance and minimizing stressful conditions.

This study was conducted on 70 diseased Pangasius hypophthalmus fish collected from different Pangasius fish farms in Egypt. Bacteriological examination revealed the isolation of P. aeruginosa that was biochemically confirmed using MALDI-TOF MS and VITEK 2 compact system. The prevalence and virulence of Pseudomonas aeruginosa were estimated genotypically using species-specific 16S rDNA gene, OprL and ToxA virulent genes for detection of pathogenic strains followed by sequencing analysis. Pathogenicity of isolated Pseudomonas aeruginosa was confirmed by experimental intraperitoneal injection of healthy Pangasius hypophthalmus with positively virulent strains resulting in high mortalities among injected fish.

Brucellosis in dromedary camel bulls leads to either temporary or permanent loss of fertility. Camel brucellosis is associated with both orchitis and epididymitis. However, the clinical signs of camel brucellosis are not clear as those in cattle. Therefore, this study aimed to diagnose camel brucellosis based on a serological screening using Rose Bengal plate test (RBPT) followed by competitive ELISA. To understand the impact of brucellosis on camel bull fertility, this study aimed to examine the semen characteristics, evaluate the testicular histopathology, examine hormonal profile, antioxidants and acute phase proteins (APP). A total of 150 mature bulls were used in this study. Blood samples were collected for serological, hormonal, and biochemical analysis. This study revealed that 6.6% and 7.3% of the examined bulls were Brucella-seropositive using RBPT and competitive ELISA, respectively. The Brucella-seropositive dromedary bulls showed poor semen quality, pathological changes orchitis, and lower testosterone. Moreover, our findings showed a higher cortisol level, and significant impairments in the measured APP and antioxidants in Brucella-seropositive bulls. In conclusion, the Brucella-seropositive dromedary bulls showed lower fertility due to poor semen quality and lower testosterone levels. Such lower fertility is likely mediated by high cortisol levels, and impaired APP and antioxidants’ defense response.

In the current investigation, a total of 110 Oreochromis niloticus were collected from ‎aquaculture farm at Sahl Eltina area, North Sinai Governorate suffering from skin and fin ulcers ‎with ascites, exophthalmia, and high mortalities. Aeromonas hydrophyla was isolated with a ‎prevalence rate of 40% and identified biochemically. A‏.‏‎ hydrophyla was used to induce ‎experimental infection to Nile Tilapia in which thyme and thymol were used as feed additive. ‎Evaluation of the protective effect of thyme and thymol as immunostimulant agents on fish ‎tissue against experimental infection with Aeromonas infection was studied. A total of ninety ‎apparently healthy fish tilapia were divided into three groups (GA, GB and GC of 30 fish per ‎group) in triplicate. GA (infected non treated group) was fed on basal diet. GB and GC were ‎fed on diet supplemented with Thyme vulgaris (10 g/ kg diet) and Thymol (3 g/ kg diet), ‎respectively for 8 weeks and then the groups were subjected to experimental infection with ‎Aeromonas hydrophyla isolate. The thyme and thymol groups had a nearly similar significant ‎immunostimulant effect than infected non treated group by using lysozyme activity assay. ‎Sever hyperemia of gill filaments and gill arch, epithelial desquamation of the gill filament, ‎enteritis, necrosis and desquamation of epithelial cells of intestine, muscle necrosis, ‎myocardiolysis of heart, hydropic degeneration of liver and hemosiderosis of spleen were ‎observed in infected non treated group. In the treated groups, the prophylactic effect of thyme ‎and thymol on fish tissues were clear against experimental infection with A. hydrophyla. These ‎results indicate that the using thyme or thymol as feed additive could enhance the immunity and ‎protect fish tissues from pathological deterioration induced by infection with Aeromonas ‎hydrophila which is considered as one the main fish pathogens in Egypt‎‎.

Microbial infections in tilapia aquacultures cause severe economic losses in Egypt. They appear in summer with other stress factors such as low oxygen and high ammonia levels in aquaculture. Streptococcosis lead to severe losses in tilapia farming, especially in third countries. Microbiological and histopathological examinations are very important diagnostic tools in distinguishing fish microbial infections. This study aimed to isolate, identify, and characterize the most common bacterial fish pathogen recovered from Nile tilapia private farm around El Salam Canal, at Ismailia governorate. In addition to detection the main histopathological lesions were done. The highest rate of bacterial isolation was Streptococcus agalactiae with 29.16% from all samples. Grossly the infected fish showed hemorrhagic septicemia, and exophthalmia. Histopathological examination revealed severe hyperemia of gill filaments and gill arch, chronic enteritis, hydropic degeneration of the liver, edema and hemosiderosis of the spleen, necrosis of muscle and hemorrhage and myocardiolysis of heart.

Camels (Camelus dromedarius) are the most valuable desert animals in Egypt, survive and health of camel calves is the main aim of breeders. The studies on microbial conjunctivitis of newborn camel calves after parturition and their relation to vaginal microbes are rare. Fifty pregnant she-camels were noticed till parturition. Vaginal swabs of mother camels and conjunctival swabs of their newborns were taken after parturition. From microbiological examination, several microbes could be isolated as follow; E. coli, Pseudomonas aeroginosa, Enterobacter sp., Proteus sp., Staphylococcus epidermidis, Streptococcus sp., Corynebacterium sp., Bacillus sp. and Candida sp. From vaginal and conjunctival swabs, E. coli was the predominant isolates. Molecular identification by PCR was done on selected 3 E. coli isolates from conjunctivitis swabs of newborns camel calves. Antimicrobial resistance was found in E. coli isolates to common used antibiotics. The mean results of antibiotic sensitivity were cleared. The E. coli isolates showed high resistance against 4 of tested 6 antibiotics with percentage of 66.67% which were Amoxicillin, Ampicillin, Tetracycline and Trimethoprim - Sulfamethoxazole. On the other hand, they were sensitive to only Azthromycin with percentage of 16.66% and intermediate to Streptomycin (16.67 %).The sensitivity to natural anti-microbial activity of marine microalgae (Nannocloropsis oculata) was investigated as trial to overcome antimicrobial resistance. Further studies are recommended to develop new veterinary pharmaceutical agents.