Most bacteria seek to live in harmony with their host. Some are even beneficial. One example is Oxalobacter formigenes, an intestinal bacterium associated with a reduced incidence of kidney stones, an ailment that affects some 25 million Americans over a lifetime. Scientists at the University of Florida in Gainesville have isolated two genes from this bacterium that may pave the way to gene therapy for kidney stones.
Pathology professor Ammon B. Peck and his colleagues have identified two genes that direct the production of enzymes that break down oxalic acid. Left alone, oxalic acid binds with calcium to form crystals that solidify into painful stones. Peck introduced the genes into embryonic rat tissue and will soon graft the tissue into kidneys of adult rats. The rats will be fed a high-oxalate diet to see if the genetically engineered tissue can stop the formation of kidney stones. Peck has also put one of the genes into human fetal tissue, but human trials are several years away. Ixion Biotechnology Inc., a startup in Alachua, Fla., is funding the trials and will soon market a supersensitive dipstick test for oxalic acid that was developed by the same team.