Marine Smenospongia extract mitigated co-infection with Trichodina sp. and Flavobacterium columnare in Nile tilapia: insights into promoting growth performance, immune, antioxidant and autophagy defenses, and suppression of endoplasmic reticulum stress-re
Identifying novel natural sources from the marine environment with unique
immunomodulatory and antioxidant efficacies is of interest in intensive fish
farming. In this sense, marine sponge extract derived from Smenospongia (SSextract)
was tested for its potential anti-inflammatory, antioxidant and
antimicrobial activities during the concurrent infection with Trichodina sp. and
Flavobacterium columnare in Nile tilapia. A total of 625 Nile tilapia fingerlings
were distributed into five groups: the control group (with no additives) and four
groups fed the control diet fortified with SS-extract at 50, 100, 150, and 200 mg/
kg, respectively, for 60 days. The parasitic challenge with Trichodina sp was done
at the endpoint of the feeding trial and at 7 days post-infection (dpi); the fish were
coinfected with F. columnare. A significant improvement in growth-related
parameters of Nile tilapia was detected in the groups that received SS-extract at the levels of 150 and 200 mg/kg. The scavenging ability for free radicals (2,2′-
azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-
picrylhydrazyl (DPPH)) was maximized with higher SS-extract supplementation
levels. Simultaneously, the antioxidant defense of the Nile tilapia fed 150 and 200
mg/kg was augmented with a decline in oxidation-associated indicators [reactive
oxygen species (ROS), hydrogen peroxide (H2O2), and malondialdehyde (MDA)].
The higher concentrations of SS-extract in the feed potentiated the immune
response of Nile tilapia before infection and even after coinfection and was
paralleled by a subsiding in the exaggerated inflammatory response after
concurrent infection. Concurrently, the mRNA expression of autophagyencountered
genes (Atg5 and 12, LC3-II and BCLN1) had its highest expression
in the fish fed the 200 mg/kg diet with the lowest expression of the mTOR gene
in the same fish. The lowest infection intensity and rate and mucus score were
displayed in fish fed 200 mg/kg SS-extract at 20 dpi. Interestingly, higher levels of
SS-extract triggered antimicrobial peptides (upregulation of Hepcidin and bdefensin-
1). In contrast, excessive expression of endoplasmic reticulum genes
(atf4, JAK1, PERK, and eif2a) in the control infected group was downregulated by
200 mg/kg of SS-extract. The quantification of F. columnare indicated that
columnaris coinfection severity displayed its lowest rate in the group
supplemented with 200 mg/kg of SS-extract. In conclusion, a strategic siting
based on fortification of the diet of Nile tilapia with SS-extract was elucidated to
reinforce its immune and antioxidant defenses during a concurrent infection.
Pseudomonas putida is a virulent bacterium that prompts major losses in fish. Recently, there has been a
noticeable direction for utilizing nanomaterials in the aquaculture industry for…
Identifying novel natural sources from the marine environment with unique
immunomodulatory and antioxidant efficacies is of interest in intensive fish
farming. In this sense, marine…
The present investigation proposed an innovative trial at the probable beneficial effects of nano-
Bacillus amyloliquefaciens (NBA) dietary incorporation on the Nile tilapia (Oreochromis…