PDT Kills Drug-Resistant Bacteria, Fungus

Photodynamic therapy could treat fungal infections and bacterial infections of the mouth, University at Buffalo’s School of Dental Medicine research shows.

Researchers found that the bacteria S. mutans, as well as fungal organisms of the genus Candida, cultured from HIV patients were highly susceptible to killing with minimal doses of PDT, both in laboratory dishes and on biofilms grown on denture material.

PDT may provide an adjunct to current antibiotic treatment or an alternative where antibiotics no longer are working, said Thomas S. Mang, Ph.D., associate professor of oral and maxillofacial surgery. This may be vital for patients undergoing cancer therapy, HIV patients who demonstrate resistance to antibiotics and the elderly with persistent oral infections.

Photodynamic therapy is based on the propensity of certain types of cells or organisms to absorb light-sensitive drugs. This selective retention allows researchers to direct a laser beam into the organism, activating the drug and killing the organism without damaging surrounding tissue.