Freshwater bacteria are the emerging pathogens that cause severe systemic disease in fish worldwide. Fish epidermal mucus contains innate immune components that provide the primary defense against different pathogenic microbes. The current experiment was designed to profile molecular changes of red hybrid tilapia mucus after subsequent challenge to common freshwater bacteria. Thus, to profile the epidermal mucus, 30 red hybrid tilapia Oreochromis spp. each of 150g was infected with Streptococcus agalactiae, Staphylococcus aureus, and Aeromonas hydrophila. 10 fish were infected for each bacterium, and 10 fish acted as control. Every 1, 2, 4, and 8 hours, fish body mucus was collected in order to profile and explore molecular changes after subsequent challenge towards the causative agent. Sodium Dodecyl Sulfate Polyacrylamide Gel-Electrophoresis (SDS PAGE) was used to allow the fish body mucus protein separation by mass. As a result, common protein, 14 kDa was found in all of the isolated mucus challenged. Meanwhile, a protein with a size 49 kDa, 81kDa, and 101 kDa was found as a prominent protein of Streptococcus agalactiae. The prominent protein after challenge with Staphylococcus aureus is 20 kDa, 30 kDa, 35 kDa, and 63 kDa. In contrast, the most prominent protein after challenge with Aeromonas hydrophila is 35 kDa, 40 kDa, 60 kDa. Protein profiling of mucus after 4 hours being challenged shows the best variations from the region 14-101 kDa. All of this finding is important towards better treatment and prevention of disease occurrence in Tilapia aquaculture.

 

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