How Immunity Proteins Work (IMAGE) Imperial College London Caption Top: an attacking bacteria injecting toxin into three different strains of P. aeruginosa. The Blue and green strains have different verisons of the immunity protein. The red strain has been injected with the attacker's immunity protein. Bottom: The blue and green strains are harmed and eventually die, while the red bacteria is protected Credit Imperial College London Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.