Influences of contamination of Aeromonas hydrophila, on quality, oxidative damage, and ultrastructure in cryopreserved sperm of the silver barb, Barbonymus gonionotus

• Main Author: Sooksawat T.
• Other Authors: Mahidol University
• Format: Article
• Published: 2023
• Subjects: Agricultural and Biological Sciences
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/83338

This study investigated the effects of pathogenic bacteria, Aeromonas hydrophila, contamination on the changes in sperm oxidative damage, ultrastructure, and quality in the silver barb (Barbonymus gonionotus) following cryopreservation. Suspensions of silver barb sperm were in vitro inoculated with A. hydrophila (0, 103, and 105 CFU/mL; named as control, T1, and T2, respectively) and incubated at 25 ± 1 °C for 5 min, before equilibration with 10% DMSO. Sperm samples were frozen and cryostored within a dry shipper at the upper and lower chamber, respectively. The number of A. hydrophila incubated with sperm caused sperm quality decrease and was inversely correlated with unfrozen sperm motility (r = −0.5987) and viability (r = −0.5277) and post-thaw sperm motility (r = −0.5710) and viability (r = −0.7573). The lipid peroxidation (LPO) levels were significantly (p < 0.05) affected by the in vitro inoculation of A. hydrophila and freezing condition (unfrozen or frozen). Significant (p < 0.05) inverse correlations were observed between LPO levels and sperm quality (motility and viability) of silver barb sperm. Ultrastructural damage of silver barb sperm (plasma membrane, mitochondria, flagella, and nucleus) was significantly (p < 0.05) affected by the freezing-thawing process and A. hydrophila contamination. In addition, the inoculation of A. hydrophila and cryopreservation process caused the alteration of sperm morphology at the ultrastructure level including swelling and rupture of the plasma membrane, vesicular to swollen-mitochondria, tail coiling, disarranged flagellum, chromatin condensation, and nuclear fragmentation. Our study revealed that a high level of A. hydrophila contamination and freezing-thawing process during cryopreservation process can activate the necrosis and apoptosis-like phenomenon and autophagy pathway in silver barb sperm.