Fig. 7

Model for interbacterial antagonism induced inflammation and impact on host survival. (A) Colicin-mediated killing is very effective at eliminating targeted bacteria. Because this killing is so rapid, if there are host inflammatory responses to the killed bacteria, they are short-lived, enabling the host to fully recover. T6SS is less efficient and therefore results in continuous bacterial killing and prolonged inflammatory response. (B) Health requires a balanced inflammatory response: too little enables uncontrolled pathogen growth, but too much results in host cellular damage. T6SS-mediated bacterial killing by different bacterial species impacts different parts of this scale. On one end, T6SS-induced inflammation sensitizes the host to less inherently pathogenic bacteria like A. baylyi, while on the other, suppression of inflammation by corticosteroids like dexamethasone allows pathogens like V. cholerae to grow uncontrolled. T6SS-mediated killing by V. cholerae exist in a unique place where the heightened inflammatory response it induces counterintuitively also enables it to grow unchecked. https://doi.org/10.1371/journal.ppat.1012384.g007