Lori Burrows
Professor, Biochemistry & Biomedical Sciences
(905) 525-9140 x 22029

Type IV Pili

Many species of bacteria produce long, thin, flexible appendages called type IV pili (T4P). T4P can be rapidly and repeatedly extended and retracted, allowing bacteria to capture DNA and stick to different surfaces. T4P allows bacteria to 'feel' surface contact, which then turns on the expression of surface-associated genes, such as those involved in biofilm formation. Further, T4P are receptors for bacteriophages, and can even act as wires to conduct electricity in some species. The Burrows Lab investigates multiple aspects of T4P and has many ongoing projects ranging from studying the machine that makes T4P, the motor that extends and retracts them, the diversity of the subunits that make up T4P and its relationship to phage escape, and the regulatory pathways involved in surface sensing, among other projects.


Biofilms are communities of bacteria that grow on surfaces. They make cells more tolerant of disinfectants and antibiotics, making biofilm infections difficult to treat. The Burrows Lab studies how biofilms develop in response to chemical cues, particularly antibiotics. Sub-lethal concentrations of antibiotics stimulate biofilm formation – they study how this phenotype is induced, and exploit it to identify new antimicrobials in complex mixtures or compound libraries.