Matthew R. Parsek
My research involves the study of bacterial communities. This research focuses on two aspects that are closely related. Quorum sensing is a term used to describe the regulation of gene expression according to population densities, many Gram-negative bacteria use specific signaling molecules, called acyl-homoserine lactones (acy-HSLs), to sense the presence of other bacteria of the same species in the bacterial cell membrane. At high cell densities the acyl-HSL reaches a critical concentration at which expression of quorum sensing-controlled genes is induced. Therefore, quorum sensing constitutes a rudimentary communication system between bacteria that allows them to coordinate behavior at the community level.
We are also interested in the surface-attached bacterial communities called biofilms. These bacteria are held together by an extracellular matrix. Most bacteria in the environment exist as biofilms and biofilm bacteria have been shown to possess unique characteristics that are not seen in conventional test tube-grown bacteria. It has also been estimated recently that up to 67% of bacterial infections involve biofilm bacteria. Therefore there is a growing appreciation for the need to study biofilm bacteria.
We use the opportunistic pathogen, Pseudomonas aeruginosa, as a model organism for our research. P. aeruginosa is responsible for a variety of nosocomial infections. It is also the primary infectious agent in lung infections of people suffering from Cystic Fibrosis. Recently, we determined that quorum sensing is important for normal biofilm development. This finding has important implications for understanding and controlling both clinical and environmental biofilms. We are trying to understand the mechanism of quorum sensing in biofilms at the molecular level. We also are interested in the extracellular matrix of P. aeruginosa biofilms - what is it made of? and how does it contribute to antimicrobial resistance? Our research utilizes cutting-edge technology such as scanning confocal laser microscopy and techiques from the fields of molecular biology, biochemistry, and bacterial pathogenesis.
Recent Publications from PubMed
- Social Cooperativity of Bacteria during Reversible Surface Attachment in Young Biofilms: a Quantitative Comparison of Pseudomonas aeruginosa PA14 and PAO1.Lee CK, Vachier J, de Anda J, Zhao K, Baker AE, Bennett RR, Armbruster CR, Lewis KA, Tarnopol RL, Lomba CJ, Hogan DA, Parsek MR, O'Toole GA, Golestanian R, Wong GCLmBio. 2020 02; 11 1:
- Pel Polysaccharide Biosynthesis Requires an Inner Membrane Complex Comprised of PelD, PelE, PelF, and PelG.Whitfield GB, Marmont LS, Ostaszewski A, Rich JD, Whitney JC, Parsek MR, Harrison JJ, Howell PLJournal of bacteriology. 2020 Mar; 202 8:
- Armbruster CR, Lee CK, Parker-Gilham J, de Anda J, Xia A, Zhao K, Murakami K, Tseng BS, Hoffman LR, Jin F, Harwood CS, Wong GC, Parsek MReLife. 2019 06; 8 :
- The Pseudomonas aeruginosa lectin LecB binds to the exopolysaccharide Psl and stabilizes the biofilm matrix.Passos da Silva D, Matwichuk ML, Townsend DO, Reichhardt C, Lamba D, Wozniak DJ, Parsek MRNature communications. 2019 05; 10 1: 2183
- Reichhardt C, Parsek MRFrontiers in microbiology. 2019 ; 10 : 677