Acne Bacteria Genome Decoded
May lead to development of new treatments for skin disorder
THURSDAY, July 29, 2004 (HealthDayNews) -- European scientists have sequenced the complete genome of a bacterial species involved in many cases of acne, and they're already working on potential new treatments based on that achievement.
"We have identified this target, and we want to see if we can block its enzymes that degrade tissues, and also block enzymes that interact with the immune system," said Holger Brüggemann, lead author of a report on the sequencing in the July 30 issue of Science. He took part in the research at the Georg-August University in Göttingen, Germany, and now is a postdoctoral fellow at the Pasteur Institute in Paris.
The bacterium, Propionibacterium acnes, is a common inhabitant of human skin. It usually lives in the glands that secrete oil into hair follicles. The activity of its enzymes on the oil is believed to produce substances that can trigger acne. Other factors are involved, however, including hormones.
P. acnes has also been linked to a number of other medical problems, including ulcers of the cornea, gallstone formation and endocarditis, or damage to heart tissue.
P. acnes has "quite a small genome," said Brüggemann, with only 2,333 genes compared to the 4,000 of E. coli, a common bacterium. But some of those genes code for "host-degrading enzymes," and others interact with the immune system in a way that can lead to the pimply outbreaks of acne, he said.
Dermatologists would welcome a more targeted treatment of acne, Brüggemann said. "Nowadays if you have acne you get treated with antibiotics, which have side effects," he said. "We don't want to kill all the bacteria, only the ones that cause acne."
A new treatment would be helpful because "patients are increasingly concerned about antibiotics," said Dr. Susan Goodlerner, a spokeswoman for the American Academy of Dermatology.
That concern has led to increasing use of phototherapy, a blue-light treatment, Goodlerner said. But treatment usually starts with topical antibiotic treatment, a salve spread on the skin.
Topical antibiotics help most patients, but "some people seem to be resistant to antibiotics," Goodlerner said. Phototherapy is the next step for such patients.
As a last resort, if antibiotics and phototherapy fail, the dermatologist can use Accutane (isotretinoin), "which works in the most severe acne," she said.
But Accutane is known to cause birth defects, including brain and heart damage and cleft lip and palate. The U.S. Food and Drug Administration instituted a voluntary testing and contraceptive program for women considering Accutane, but a statement by the March of Dimes Birth Defects Foundation in February said "major birth defects caused by exposure to Accutane and other brands of isotretinoin...continue to occur in the United States."
Accutane has also been implicated, but not proven, in cases of suicide.
"There is always room for new, effective treatments," Goodlerner said.
Learn about acne and its treatments from the National Institute of Arthritis and Musculoskeletal and Skin Diseases.