University of Pittsburgh-led researchers discovered the primary bacteria behind tuberculosis can grow on surfaces and that drug-tolerant strains flourish in such bacterial communities. The finding, the scientists said, suggests a possible reason why human TB requires months of intensive antibiotic treatment and indicates a potential cause of the relapses that can occur.

The researchers said they are the first to show Mycobacterium tuberculosis can grow in surface-level bacteria clusters known as biofilms that are common in nature, but never before shown for TB bacteria.

The study was led by Professor Graham Hatfull of the University of Pittsburgh and Professor William Jacobs Jr. of the Albert Einstein College of Medicine in New York. Collaborators included Yann Guerardel and Xavier Trivelli of the Lille University of Science and Technology in France, Laurent Kremer and Anuradha Alahari of France's University of Montpellier; University of Pittsburgh postdoctoral researcher Anil Ojha; and Jacobs' research associates Anthony Baughn, Dhinakaran Sambandan and Tsungda Hsu.

The research was reported recently in the journal Molecular Microbiology.