Hindering the biofilm of microbial pathogens and cancer cell lines development using silver nanoparticles synthesized by epidermal mucus proteins from Clarias gariepinus.

Scientists know very little about the mechanisms underlying fish skin mucus, despite the fact that it is a component of the immune system. Fish skin mucus is an important component of defence against invasive infections. Recently, Fish skin and its mucus are gaining interest among immunologists. Characterization was done on the obtained silver nanoparticles Ag combined with Clarias gariepinus catfish epidermal mucus proteins (EMP-Ag-NPs) through UV-vis, FTIR, XRD, TEM, and SEM. Ag-NPs ranged in size from 4 to 20 nm, spherical in form and the angles were 38.10°, 44.20°, 64.40°, and 77.20°, Where wavelength change after formation of EMP-Ag-NPs as indicate of dark brown, the broad band recorded at wavelength at 391 nm. Additionally, the antimicrobial, antibiofilm and anticancer activities of EMP-Ag-NPs was assessed. The present results demonstrate high activity against unicellular fungi C. albicans, followed by E. faecalis. Antibiofilm results showed strong activity against both S. aureus and P. aeruginosa pathogens in a dose-dependent manner, without affecting planktonic cell growth. Also, cytotoxicity effect was investigated against normal cells (Vero), breast cancer cells (Mcf7) and hepatic carcinoma (HepG2) cell lines at concentrations (200-6.25 µg/mL) and current results showed highly anticancer effect of Ag-NPs at concentrations 100, 5 and 25 µg/mL exhibited rounding, shrinkage, deformation and granulation of Mcf7 and HepG2 with IC50 19.34 and 31.16 µg/mL respectively while Vero cells appeared rounded at concentration 50 µg/mL and normal shape at concentration 25, 12.5 and 6.25 µg/ml with IC50 35.85 µg/mL. This study evidence the potential efficacy of biologically generated Ag-NPs as a substitute medicinal agent against harmful microorganisms. Furthermore, it highlights their inhibitory effect on cancer cell lines.

Effect of replacing fish meal in fish diet with shrimp by-product meal on growth performance, feed utilization, length-weight relationship and condition factors of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) / Efecto de reemplazar la harina de pescado en la dieta de pescado por harina de subproducto de camarón sobre el rendimiento del crecimiento, la utilización del alimento, la relación longitud-peso y los factores de condición de la tilapia del Nilo, Oreochromis niloticus (Linnaeus, 1758)

SUMMARY: The present work aimed to study the effect of replacing fish meal (FM) in the fish diet with shrimp by-product meal (SBM) on the growth performance parameters of the Nile Tilapia, Oreochromis niloticus. A total of 200 specimens of monosex O. niloticus fries were obtained from a private fish farm at Kafr El-Sheikh Governorate. They were transported to the fish laboratory at the Animal House of Zoology Department, Faculty of Science, Al-Azhar University. After two weeks for acclimation, the fish were divided into 5 groups, 2 replicates for each group (20 fish in each replicate). The five experimental diets were: C: control group with20 % fish meal (FM) and 0 % shrimp by-product meal (SM); T1, T2, T3, and T4 FM was replaced with SBM as 25 %, 50 %, 75 % and 100 %, respectively. Results indicated that the highest final length, growth in length, length gain, daily length gain and other growth performance parameters including the relationship between length and weight and condition factors of O. niloticus were recorded in T4 group (fed diet in which fish meal was completely replaced with shrimp by-product meal); while, their lowest values were recorded in control group. On the other hand, feed utilization parameters (feed intake, food conversion ratio, the maximum values of feed efficiency ratio and protein efficiency ratio) were recorded in T4 group and the minimum values were recorded in T3 group (fed diet in which 75 % of fish meal was replaced with shrimp by-product meal).

RESUMEN: El presente trabajo tuvo como objetivo estudiar el efecto de sustituir la harina de pescado (HP) en la dieta del pescado por harina de subproductos de camarón (HSC) sobre los parámetros de rendimiento de crecimiento de la Tilapia del Nilo, Oreochromis niloticus. Se obtuvieron un total de 200 especímenes de monosexo de O. niloticus de una piscifactoría privada en la gobernación de Kafr El-Sheikh. Fueron transportados al laboratorio de peces en el Departamento de Zoología de la Facultad de Ciencias, de la Universidad Al-Azhar. Después de dos semanas de aclimatación, los peces se dividieron en 5 grupos: Se realizaron dos repeticiones para cada grupo (20 peces en cada repetición). Las cinco dietas experimentales fueron: C: grupo control con 20 % de harina de pescado (HP) y 0 % de harina de subproductos de camarón (HSC); T1, T2, T3 y T4 FM se reemplazó con HSC con 25 %, 50 %, 75 % y 100 %, respectivamente. Los resultados indicaron que la longitud final más alta, el crecimiento en longitud, la ganancia de longitud, la ganancia de longitud diaria y otros parámetros de rendimiento del crecimiento, como además la relación entre la longitud y el peso, y los factores de condición de O. niloticus, se registraron en el grupo T4 (con una dieta reemplazada con harina de subproducto de camarón); mientras que, sus valores más bajos se registraron en el grupo control. Por otro lado, los parámetros de utilización del alimento (ingesta de alimento, índice de conversión de alimento, los valores máximos de índice de eficiencia alimenticia e índice de eficiencia proteica) se registraron en el grupo T4 y los valores mínimos se registraron en el grupo T3 (alimentación con dieta en la que el 75 % de la harina de pescado fue reemplazada por harina de subproductos de camarón).