In a major achievement, Southwest Foundation for Biomedical Research (SFBR) in San Antonio researchers has constructed a genetic map of the parasite that causes schistosomiasis.
Schistosomiasis is a chronic intestinal infection that can damage internal organs and, in children, impair growth and cognitive development.
Schistosome parasites are flatworms that infect more than 200 million people a year worldwide.
"A genetic map is the essential tool needed for finding the genes that are responsible for drug resistance and pathogenesis in this parasite. In the case of drug resistance, identification of underlying mutations is critical for management of this disease," said Dr. Timothy Anderson, of SFBR's department of genetics.
He added: "First, identification of mutations allows us to better understand the mechanism of action of the drugs used, and to redesign drugs to restore treatment efficacy. Second, identification of mutations involved allows us to efficiently monitor the spread of resistance in parasite populations using simple molecular methods."
For the study, the researchers used two adult flatworms to breed 88 S. mansoni offspring.
They then compared the genetic information of the offspring to the parents, and generated a genetic map of chromosomes of the pathogen.
These parasites have a complex lifecycle. Adult male and female worms measuring around half an inch, live in pairs in the blood vessels, and eggs are expelled in the faeces or urine.
The larval parasites initially develop in water snails and human infection occurs when parasite larvae burrow through the skin of people entering the water.
The researchers are planning further research using the genetic map to understand why some parasites cause more pathology than others.
The new study has been published in the journal Genome Biology.