16.03.2012

Liu et al (2012) Cell Host & Microbe 11:227-239

Lead researcher Manuela Raffatellu, a UCI assistant professor of microbiology & molecular genetics, and colleagues identified a novel molecular mechanism that allows Salmonella to survive. Results of their study appear in the March issue of Cell Host & Microbe.
One of the body's key immune responses is to flood the infected area with antimicrobial proteins that include calprotectin, which removes zinc. Without enough of this vital element, most pathogens eventually die. Salmonellae overcome this immune response by expressing specialized high affinity transporter proteins that enable the bacteria to acquire zinc in spite of calprotectin reducing the amount available in the digestive tract. This distinctive mechanism lets salmonellae continue proliferating. At the same time, calprotectin inadvertently promotes Salmonella growth by killing the microbes that normally reside within the intestines and help the immune system battle pathogenic bacteria.