Impacts of Fortifying Nile Tilapia (Oreochromis niloticus) Diet with Different Strains of Microalgae on Its Performance, Fillet Quality and Disease Resistance to Aeromonas hydrophila Considering the Interplay between Antioxidant and Inflammatory Response

Abstract

The oxidative stress facing fish during intensive production brings about diseases and mortalities that negatively influence their performance. Along with that, the increased awareness of omega-3 polyunsaturated fatty acids (omega-3-PUFAs) health benefits has been triggered the introduction of alternative additives in aqua feed that cause not only modulation in fish immune response but also fortification of their fillet. In this context, the role of microalgae mix (NSS) containing Nannochloropsis oculate and Schizochytrium and Spirulina species, which were enriched with bioactive molecules, especially EPA and DHA, was assessed on Nile tilapia’s performance, fillet antioxidant stability, immune response, and disease resistance. Varying levels of NSS (0.75, 1.5, and 3%) were added to Nile tilapia’s diet for 12 weeks and then a challenge of fish with virulent Aeromonas hydrophila (A. hydrophila) was carried out. Results showed that groups fed NSS, especially at higher levels, showed an improved WG and FCR, which corresponded with enhanced digestive enzymes’ activities. Higher T-AOC was detected in muscle tissues of NSS3.0% fed fish with remarkable reduction in ROS, H2O2, and MDA contents, which came in parallel with upregulation of GSH-Px, CAT, and SOD genes. Notably, the contents of EPA and DHA in fillet were significantly increased with increasing the NSS levels. The mean log10 counts of pathogenic Vibrio and Staphylococcus species were reduced, and conversely, the populations of beneficial Lactobacillus and Bacillus species were increased more eminent after supplementation of NSS3.0% and NSS1.5%. Moreover, regulation of the immune response (lysozyme, IgM, ACH50, NO, and MPO), upregulation of IL-10, TGF-β, and IgM, and downregulation of IL-1β, TNF-α, HSP70, and COX-2 were observed following dietary higher NSS levels. After challenge, reduction in A. hydrophila counts was more prominent, especially in NSS3.0% supplemented group. Taken together, the current study encourages the incorporation of such microalgae mix in Nile tilapia’s diet for targeting maximum performance, superior fillet quality, and protection against A. hydrophila.

Future impact of thymoquinone-loaded nanoemulsion in rabbits: prospects for enhancing growth, immunity, antioxidant potential and resistance against Pasteurella multocida

“…In accordance, dietary fortifications with liposomal encapsulated TQ elevated the levels of T-AOC, CAT antioxidant enzyme and decreased the level of MDA in rabbits ( 68 ). Furthermore, dietary inclusion of microalgae mixture increased the activities of T-AOC and GPX, CAT and SOD antioxidant enzymes and decreased the level of MDA in fish, which enhanced the cells’ resistance to oxidative stress ( 69 ). Numerous studies have stated that TQ has antioxidant properties, which are responsible for eliminating free radicals and provide a significant improvement to oxidative stress responses ( 19 , 70 , 71 ).…”

A new pathogenic isolate of Kocuria kristinae identified for the first time in the marine fish Larimichthys crocea

“…In recent years, it has been reported that some common and emerging bacterial strains isolated from diseased marine fish have homologies with pathogens that were originally found in human infections ( Rodriguez et al, 2016 ), such as V. parahaemolyticus ( Guin et al, 2019 ), S. agalactiae ( Kalimuddin et al, 2017 ), H. pylori ( Abdel-Moein et al, 2015 ), Aeromonas spp. ( Borella et al, 2020 ; Ibrahim et al, 2022a , b ), E. coli , Shigella spp., Salmonella spp., L. monocytogenes , Weissella spp. ( Castrejón-Nájera et al, 2018 ), Rahnella spp.…”

“…in seabreams; furthermore, the fungal pathogens Saprolegnia spp. and the parasites Trichodina , Chilodonela , Argulus , and Ergasilus , as well as Leeches have been known for a long time ( Kim et al, 2017 ; Buján et al, 2018 ; Duman et al, 2021 ; Abd El-Hack et al, 2022 ; Shahin et al, 2022 ; Ibrahim et al, 2022a , b ). However, many unknown or emerging etiological diseases still appear frequently in aquatic farms, seriously affecting the development of aquaculture ( Shahin et al, 2022 ).…”

Role of Dietary Microalgae on Fish Health and Fillet Quality: Recent Insights and Future Prospects

“…It was concluded that dietary S. platensis can be recommended to counteract the oxidation induced by sodium sulphate toxicity in fish species. A 12-week feeding Nile tilapia with microalgae mixture (Nannochloropsis oculate, Schizochytrium and Spirulina species) at 0.75%, 1.5%, and 3% exhibited a higher antioxidant capacity and reduced ROS, H2O2, and MDA levels especially at 3% inclusion [88], Meanwhile, contents of EPA and DHA in tilapia fillet were significantly enhanced with an increase in NSS (microalgae mix (NSS) containing Nannochloropsis oculate and Schizochytrium and Spirulina species) levels. Such antioxidant activity could be in part due to the availability of tocopherols, phenolic compounds, and carotenoids that can reduce the oxidative stress responses in different fish species [88].…”