When Dawn Bowdish thinks of her 90-year-old grandparents, the importance of her
research becomes real. It would be easy for them to become a statistic – one of the
thousands of elderly Canadians who die each year of pneumonia, influenza or a
combination of both.

This year has been particularly tough, with the influenza strain affecting more elderly
than in years past. But with a $100,000 Young Investigator Grant from Pfizer Canada,
the assistant professor of Pathology and Molecular Medicine and member of the
Michael G. DeGroote Institute for Infectious Disease Research (IIDR) will help
researchers better understand why the elderly are so at risk.

“In some nursing homes the death rate from pneumonia can be as high as 25 per cent
over the winter season, so we know we have to be creative and bold to find treatments
because this is not acceptable,” said Bowdish. “Not only is it hard on the family but on
the health care system. Surprisingly, we don't know how many of these deaths in the
elderly are due to bacterial pneumonia, viral influenza or a combination of both.”

The grant will support the study of why the elderly are at increased risk of pneumonia
and how a co-infection with the influenza virus is particularly dangerous for them. It
will also allow Bowdish to test a novel prophylactic therapy, using an antibiotic
developed by Pfizer Canada. In studies with elderly mice, Bowdish and her team are
looking at ways to administer the drug intranasally in an effort to clear the colonization
of bacteria in the upper respiratory tract. They hope that this will protect this at-risk
group from both pneumonia caused by the bacteria directly and also pneumonia that
arises after an influenza infection.

“It's a bold strategy that might really help people,” said Bowdish. “We are testing this in
our aged mouse models and hoping to secure funding to bring it to people locally.”

Her studies look at macrophages, the sentinel cells that shape one's immune response,
and the role they play in infectious disease. These cells, Bowdish explains, play a
leading role in controlling the bacteria that causes the majority of pneumonias.

Her lab is one of the first in Canada to study elderly mice models in combination with a
cohort of elderly humans living in nursing homes.

“Even understanding the mechanisms by which this disease is caused in this huge
portion of our population is really going to be important,” she said. “We still won't
understand the mechanisms of where this breaks down but we will understand where
we should focus our research strategy.”

Bowdish is conducting the studies in collaboration with IIDR investigator Jennie
Johnstone, clinical scholar in the Department of Medicine.