Lake sturgeon harbor protozoan parasite

WEST LAFAYETTE, Ind., May 18 (UPI) -- A U.S. study suggests some lake sturgeon might harbor a protozoan parasite that can cause a sexually transmitted disease in humans.

Purdue University Professor Andrew DeWood and postdoctoral researcher Matthew Hale said they made the discovery while attempting to find a DNA-based test to determine the sex of lake sturgeon. The only way to determine a lake sturgeon's sex currently is to examine its internal sexual organs.

DeWoody said about 15 genes found in the lake sturgeon came from Schistosoma, a parasitic worm. Lateral gene transfer from one organism to another is rare, especially in multicellular animals, he said, but could be part of some evolutionary process for the sturgeon.

While lateral gene transfer from a trematode worm could ultimately benefit the lake sturgeon, evidence of the Trichomonas pathogen is more likely to have a negative effect. The Centers for Disease Control and Prevention said a human version of the pathogen causes trichomoniasis, a common sexually transmitted disease that mostly affects women and can cause pregnant women to deliver early or have children with lower birthweights.

The finding is the first suspected case of Trichomonas in a fish, DeWoody said.

The research appears in the early online version of the journal Genetica.