BUFFALO, N.Y. -- Patients admitted to a hospital's intensive
care unit (ICU) already are seriously ill, so the last thing they
need is a new infection.
Unfortunately, statistics show that as many as 25 percent of all
patients admitted to the ICU and placed on ventilators develop
pneumonia, which can be fatal.
Ventilator-associated pneumonia is a major cause of infection in
the hospital, and studies have shown that this infection can add
$40,000 to costs and double the length of stay of the patient in
Ironically, it turns out that the patient's own dental plaque is
a major source of germs that cause ventilator-associated
In results to be presented today (March 23, 2007) at the
International Association of Dental Research (IADR), researchers
from the University at Buffalo School of Dental Medicine show that
the same bacteria identified in dental plaque of patients when they
were admitted to the ICU and placed on ventilators were found later
in the lungs from those who subsequently developed pneumonia.
"Our study shows that a strong relationship exists between oral
and respiratory pathogens in patients with ventilator-associated
pneumonia," said Paul Heo, D.D.S., a doctoral student in the UB
dental school's Department of Oral Biology and first author on the
"We are saying that if the patients' mouths and teeth aren't
cleaned while they are in the hospital, they may easily develop
The presentation is part of a three-year longitudinal,
double-blind study funded by the National Institute of Dental and
Craniofacial Research and headed by Frank A. Scannapieco, D.D.S.,
Ph.D., professor and chair of the Department of Oral Biology.
The trial aims to determine if swabbing ventilated ICU patients'
mouths with a bactericide protects them from developing
In this component, Heo and colleagues concentrated on three
strains of suspected pathogens that are responsible for most
hospital-acquired pneumonia: Staphylococcus aureus, Escherichia
coli and Pseudomonas aeruginosa. Samples of plaque from teeth and
of secretions from the trachea were obtained from ICU patients on
the day of admission and every third day thereafter, up to 21 days.
Bronchial alveolar lavage samples also were collected from those
suspected of having developed pneumonia.
Samples from nine patients who were found to have the pathogens
of interest in their plaque and were suspected of having pneumonia
were selected for analysis. Protein and DNA profiles of pathogens
in plaque and in bronchial alveolar lavage samples were identified
using a process called pulsed-field gel electrophoresis.
Results showed that genetic profiles of bacteria from tracheal
and bronchial samples of the nine patients with pneumonia were
identical to profiles of bacteria from their dental plaque.
"These results suggest that the teeth likely serve as an
important reservoir of infection in these patients," said Heo. "To
prevent opportunistic, hospital-acquired disease, taking care of
teeth and gums while hospitalized might be especially
Elaine M. Haase, Ph.D., research associate professor of oral
biology, also contributed to the study.
The University at Buffalo is a premier research-intensive
public university, the largest and most comprehensive campus in the
State University of New York. The School of Dental Medicine is one
of five schools that constitute UB's Academic Health Center.