Impact of Staphylococcus aureus Infection on Reproductive Hormones and Gonadal Development in African Catfish (Clarias gariepinus): Implications for Aquaculture Sustainability

Abstract

The reproductive health of aquaculture species is critical for sustainable production, yet it is often threatened by bacterial infections. This study investigated the effects of experimental Staphylococcus aureus infection on the reproductive hormone profiles and gonadosomatic index (GSI) of African catfish (Clarias gariepinus), a species of significant economic importance. Thirty healthy male and female catfish were divided equally into control and infected groups. The infected groups were fed 1.5 mL of 1.5 × 108 CFU/mL of S. aureus, while the control groups received sterile phosphate-buffered saline. Hormonal levels, including testosterone, estradiol, follicle-stimulating hormone (FSH), and luteinizing hormone (LH), were measured over three weeks using enzyme-linked immunosorbent assay (ELISA), and the results revealed significant reductions (p < 0.05) in all measured hormones in the infected groups compared to the controls. Testosterone levels in infected males declined by 21%, while estradiol levels in infected females were 28% lower than in controls. Similarly, FSH and LH levels in infected males and females showed consistent decreases of approximately 20–25%. The GSI values in infected fish were significantly reduced (p < 0.05), indicating impaired gonadal development. These findings suggest that S. aureus infection disrupts the hypothalamic-pituitary-gonadal axis, likely through systemic inflammation and oxidative stress, resulting in compromised reproductive function. The findings underscore the need for stringent biosecurity measures, such as regular water quality monitoring and disinfection protocols, to mitigate the impact of S. aureus outbreaks in aquaculture systems.