CAT and infection: The pathogenic sequence of Salmonella typhimurium – another causative agent of bacteremia in humans – to cause infection when injected into mice by the intraperitoneal route, is also indifferent to the presence of either catalase [25], AhpC or OxyR [26] (which regulates transcription of about 30 proteins in response to fluctuating H2O2-levels [27]), while a severe attenuation in virulence is noticeable for a Salmonella typhimurium recA mutant defective in DNA repair [25].