Genome sequencing of schistosomiasis parasites could promote drug development

Jul 16 2009

Researchers have sequenced the genomes of two parasites that cause bilharzia or schistosomiasis - a disease transmitted by water-borne snails that affects more than 200 million people worldwide - "revealing potential weaknesses that could be exploited by drug developers," Nature reports (Smith, 7/15).

The study, which was published on Wednesday in the journal Nature, was conducted by two international teams of scientists that identified the genetic chemical sequences of two of the five harmful species of the parasite, S. mansoni and S. japonicum, Press Association/Google.com reports (7/15).

Researchers found that S. masoni, "the most widespread of the schistomiasis parasites," is comprised of almost 12,000 genes - "about 10 times the size of the malaria parasite genome," according to the BBC. The analysis also found that S. mansoni does not have "a key enzyme needed to make essential fats, and must rely on its host to provide these - revealing a potential Achilles' heel" that could be used to create new drugs, the BBC writes (7/16). 

The study "explores cost effective ways to develop new therapies, such as the possibility that existing pharmaceutical drugs might be used to target schistosomiasis," according to a University of Maryland press release (7/15).

The drug praziquantel, which is "cheap" and "effective," is currently used to treat the disease, but the concern has been that it "does not prevent people from getting re-infected by bathing in infested waters, and reinfection offers plenty of opportunities for the parasite to become resistant," according to AFP/Yahoo! News. Anthony Fauci - director of U.S. National Institute of Allergy and Infectious Diseases, which funded a portion of the research - said, "Chronic infection with schistosoma parasites makes life miserable for millions of people in tropical countries around the globe." He added, "New drugs and other interventions are badly needed" (7/15).