Specifically, we examined: (i) tissue-specific changes in immune-related enzymatic activities (SOD, CAT, LZM, Na+/K+-ATPase) and oxidative stress markers (MDA); (ii) differential gene expression and immune signaling pathway activation at 72 hours post-infection; and (iii) mechanistic links between immune enzyme activity and transcriptomic regulation of host defenses. Here, CAT is linked to infection.