New study discovers why "persister" cells never say die

Northeastern University today announced that biologist Kim Lewis has discovered the gene that prevents antibiotics from
successfully destroying infections within biofilm. For years, scientists have struggled to understand why a certain type of
infection - known as biofilms - are often resistant to antibiotics. Biofilms contain cells that are identical to the
infecting cells, but are not corrupted and destroyed by antibiotics. Lewis discovered these "persister" cells, contain a gene
(HipA) that generates a toxin (the ReIE toxin) which puts the cell into hibernation and because antibiotics must work on
growing cells to destroy them, the hibernating cells can outlast the antibiotic and then repopulate the infection.


The results of the study appears in the most recent issue of the Journal of Bacteriology, titled "Specialized Persister Cells
and the Mechanism of Multidrug Tolerance in Escherichia coli." Lewis, the lead author, worked with NU graduate students Iris
Keren, Devang Shaw and Amy Spoering , as well as Niilo Kaldalu of Tartu University in Estonia.


" The implications for the discovery are significant; medical science is racing the clock against increasingly drug-tolerant
infections. Biofilm infections are notoriously difficult to stamp out. Armed with the knowledge of the HipA gene that allows
the infections to persist, sometime for years, biologists can look for ways to deactivate the gene and wipe out the
infection," says Lewis.


Biofilm infections, which attach to a surface while encased in a membrane, typically attack surgically implanted medical
devices, such as mechanical heart valves or artificial joints. They can also take the form of periodontal disease, ear
infections or fatal lung infections. The infection can be nearly impossible to eradicate, requiring implants to be removed at
great risk and cost. Deleting or deactivating the HipA gene could save thousands of lives and millions of dollars.


About Northeastern


Northeastern University, located in the heart of Boston, Massachusetts, is a world leader in practice-oriented education and
recognized for its expert faculty and first-rate academic and research facilities. Northeastern integrates challenging
liberal arts and professional studies with the nation's largest cooperative education program. Through co-op, Northeastern
undergraduates alternate semesters of full-time study with semesters of paid work in fields relevant to their professional
interests and major, giving them nearly two years of professional experience upon graduation. The majority of Northeastern
graduates receive a job offer from a co-op employer. Cited for excellence three years running by U.S. News & World Report,
Northeastern has quickly moved up into the top half of the "Best National Universities" rankings-an impressive 30 spots in
three years. In addition, Northeastern was named a top college in the northeast by the Princeton Review 2003/04. For more
information, please visit Northeastern University.


Contact: Genevieve Haas

g.haasneu

617-373-5470

Northeastern University