Evolutionary dynamics of Tn916 in Streptococcus oralis: Fitness cost and persistent metabolic shifts post-acquisition

The acquisition of Tn916 imposes initial fitness cost on S. oralis, but the cost is rapidly mitigated through evolution, leading to competitive advantages in the long term. However, the persistence of lower maximum metabolic rate indicates that Tn916 acquisition affects cellular functions beyond growth, underscoring the need to monitor metabolic activity to fully understand the impact of horizontal gene transfer, MGEs, and ICEs on bacterial populations.