Faculty Research – Who’s Who in SOD Dr Janina Lewis
Dr Lewis was on the path to train to be an MD but after volunteering her services in the laboratory of Dr. Louise Temple in the VCU Department of Microbiology she was bitten by the research bug. This inspired her to enroll as a PhD student in the laboratory of Dr. Frank Macrina. She is now an associate professor in the VCU Phillips Institute for Oral Health Research in the School of Dentistry where her laboratory researches P. gingivalis.
Dr Lewis was initially drawn to research on microbes under the illusion that they were small simple organisms that could be used to answer some complex questions. Experience has shown her that although they are small their complexity combined with a vast array of strains, means that things are not so simple. However they are organisms that are easy to manipulate and their role in infectious disease makes them incredibly important.
Her PhD research was to investigate antibiotic resistance but initial observations made by her in Dr. Macrina’s laboratory led her to work on iron uptake. Iron uptake is essential for the survival of P. gingivalis, by identifying the metal transporters for iron uptake Dr Lewis’ laboratory has shown that mutations in these transporters can affect the ability of P. gingivalis to grow as well as survive with host cells. This may provide a mechanism to specifically target P. gingivalis in vivo and treat or prevent periodontal disease.
Interestingly P. gingivalis a member of a larger group of bacteria called Bacteroidetes where many are are commensal in the gut and are being studied for their role in prevention of obesity (http://www.ncbi.nlm.nih.gov/pubmed/24009397). As Bacteroidetes are distantly related to gamma-proteobacteria to, Dr. Lewis’ work on biology of P. gingivalis may also shed light on biology of other organisms belonging to this group of bacteria and her work may have impact beyond periodontal disease.
Other mechanisms that may be used to target P. gingivalis include understanding how it withstands the high levels of nitrosative stress it is exposed to in the oral cavity. Dr Lewis’ lab has identified a P. gingivalis gene that appears to be protective against exposure to nitrosative stress and shows that the regulatory mechanisms differ from those in E. coli. Targeting this pathway by both direct (eg therapeutic inhibitors that would reduce the tolerance of the bacterium to nitrite) or indirect (eg increased amounts of dietary nitrate) may provide a way to control periodontal disease.
There are five graduate students in the Lewis laboratory and Dr. Lewis takes her role in training the next generation of oral health researchers very seriously. Her initial research experience was in a large laboratory where she was guided and mentored by post-doctoral and doctoral students. She would like to replicate the same environment in her laboratory. She also finds that the enthusiasm and alternative approach of students helps keep her research and her ideas fresh. Some of the students in Dr. Lewis’s lab are aspiring dentists and will use their research experience to enhamce their application to dental school.
While working in a dental setting certainly makes her research feel more relevant she is aware that she does not always avail of all the opportunities that this can afford her as a research scientist but she is always open to exploring research ideas with clinical faculty and research faculty from different disciplines.
Over the coming years Dr. Lewis plans to research the interplay between iron uptake and nitrosative stress in P. gingivalis with the hope of coming closer to a treatment for periodontal disease.
Dr. Lewis enjoys her research she says. “To be a good researcher takes a lot of hard work but the rewards are enormous. I love what I do and I feel so lucky that early in my career senior faculty took the time to mentor and encourage me. I want to do the same for my students. I want them to be able to enjoy and appreciate the exciting world of research, to attend scientific meetings and to be inspired by other people’s discoveries. This is the way we advance treatment of disease.”
Read Dr Lewis’ papers on P. gingivalis and Prevotella
Categories Research