SYDNEY, March 17 (Xinhua) -- Nose lining damage, such as those caused by colds and allergies, increases the risk of bacteria entering the brain and can lead to major long-term health problems, according to a latest Australian research.
Australian scientists have discovered that damage to the lining of the nasal cavity may increase the risk of the Burkholderia pseudomallei bacterium invading the brain, according to a Griffith University statement on Tuesday.
The bacterium causes the disease melioidosis, which is endemic to northern Australia and Southeast Asia. It has high mortality and can sometimes affect the central nervous system or brain and spinal cord, the university said.
"We have previously shown that, within 24 hours, B. pseudomallei can enter the central nervous system via peripheral nerves extending between the nasal cavity and the brain, bypassing the blood-brain barrier," researcher Heidi Walkden said.
The new study showed that prior injury to the nasal lining, such as that caused by colds, allergies and traumatic injuries, "can increase the bacterial invasion of the olfactory nerve which mediates the sense of smell and leads directly from the nasal cavity into the brain". Infection of the nerve can "strongly increase the risk for central nervous system infections," according to the researchers.
Their findings showed that bacteria may sneak into the brain "unnoticed," potentially causing serious long-term problems, Walkden said.
"Bacteria and viruses, and resultant neuroinflammation, may even contribute to neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases," she said.
"This research raises the question how often our brains are really exposed to infection. Because damage to the olfactory epithelium is common and the olfactory nerve normally regenerates quickly, such injuries are usually not noticed except when people dramatically lose their sense of smell."
The research also showed that when the bacteria invade the olfactory nerve, peripheral nerve cells "become infected and form abnormal giant cells. These cells are usually important defenders against bacteria, but in this case, they become infected and diseased." The findings were published in scientific journal PLOS Neglected Tropical Diseases.
"While the studies were conducted in mice, humans have the same nerves and can be infected by the same bacteria, so we believe the results are translatable to humans," Walkden said.
"The findings in this study may also in the future pave the way for new treatments, including preventative treatment, for central nervous system infections and the long-term problems that they cause."
