The bacteria that cause acne live on everyone's skin, yet one in five people is lucky enough to develop only an occasional pimple over a lifetime.
In a boon for teenagers everywhere, a UCLA study conducted with researchers at Washington University in St. Louis and the Los Angeles Biomedical Research Institute has discovered that acne bacteria contain "bad" strains associated with pimples and "good" strains that may protect the skin.
The findings, published in the Feb. 28 edition of the Journal of Investigative Dermatology, could lead to a myriad of new therapies to prevent and treat the disfiguring skin disorder.
"We learned that not all acne bacteria trigger pimples - one strain may help keep skin healthy," said principal investigator Huiying Li, an assistant professor of molecular and medical pharmacology at the David Geffen School of Medicine at UCLA. "We hope to apply our findings to develop new strategies that stop blemishes before they start, and enable dermatologists to customize treatment to each patient's unique cocktail of skin bacteria."
The scientists looked at a tiny microbe with a big name: Propionibacterium acnes, bacteria that thrive in the oily depths of our pores. When the bacteria aggravate the immune system, they cause the swollen, red bumps associated with acne.
Using over-the-counter pore-cleansing strips, LA BioMed and UCLA researchers lifted P. acnes bacteria from the noses of 49 pimply and 52 clear-skinned volunteers. After extracting the microbial DNA from the strips, Li's laboratory tracked a genetic marker to identify the bacterial strains in each volunteer's pores and recorded whether the person suffered from acne.
Next, Li's lab cultured the bacteria from the strips to isolate more than 1,000 strains. Washington University scientists sequenced the genomes of 66 of the P. acnes strains, enabling UCLA co-first author Shuta Tomida to zero in on genes unique to each strain.
"We were interested to learn that the bacterial strains looked very different when taken from diseased skin, compared to healthy skin," said co-author Dr. Noah Craft, a dermatologist and director of the Center for Immunotherapeutics Research at LA BioMed at Harbor-UCLA Medical Center. "Two unique strains of P. acnes appeared in one out of five volunteers with acne but rarely occurred in clear-skinned people."
The biggest discovery was still to come.