Scialog: Collaborative Teams - 2015
Stanford University, Physics
Uncovering Essential Gene Functions by Exploiting Differentiation within a Biofilm
“Biofilms” are composed of single celled organisms that stick together on a surface – this includes bacteria embedded within self-produced slime that thrive in host organisms such as humans. The individual cells use chemical signaling to act as organized cooperative communities. Scientists study biofilms in part to understand the evolutionary process that led from single cells to interacting communities of cells and then to true multicellular organisms.
Biofilms are also studied because serious bacterial biofilm infections, such as pneumonia in cystic fibrosis patients, chronic wounds, and implant- and catheter-associated infections, afflict millions of people and, depending on the type of bacteria involved, kill many victims every year.
“The important hallmarks of chronic biofilm-based infections are extreme resistance to antibiotics and many other conventional antimicrobial agents, and an extreme capacity for evading the host defenses,” notes Gürol Süel, a microbiologist at the University of California, San Diego.
Süel has teamed up with Kerwyn Casey Huang, a theoretical physicist at Stanford University, to study the genetic makeup of bacteria in biofilms.
Specifically, Süel and Huang hope to test the hypothesis that growth in such a community can relieve the need of some bacteria for proteins that would otherwise be essential for their survival if they were on their own. They also hope to determine if proximity to a typical independent cell will affect the growth of a cell lacking an essential protein, whether through physical contact or chemical signaling.
To perform this research they will use advanced CRISPR/Cas technology developed in 2013 for precise gene editing and regulation. CRISPR – “clustered regularly interspaced short palindromic repeats” -- refers to short DNA base sequences followed by even shorter segments of “spacer” DNA. “Cas” refers to specific proteins that guide RNA into a cell to cut genes at specifically desired spacer locations.