“…In 2016, an outbreak of Streptococcus agalactiae resulted in high mortality rates in six tilapia farms in northeastern Brazil, causing significant economic losses for the tilapia aquaculture industry (Mian et al, 2009;Chideroli et al, 2017). The Nile tilapia (Oreochromis niloticus) has excellent growth and reproductive performance and is classified as one of the most important fish produced in Brazil and worldwide, and has been used in many studies on immunomodulators (Ha et al, 2017;Zaminhan-Hassemer et al, 2020), thus the reason for it being chosen for this study.…”