Food-poisoning parasite can evade drugs: study

A genetic analysis of a potentially deadly parasite that is a major cause of food poisoning has shed light on why the bug is so hard to treat, US researchers reported.

Food-poisoning parasite can evade drugs: studyA genetic analysis of a potentially deadly parasite that is a major cause of food poisoning has shed light on why the bug is so hard to treat, US researchers reported. A team at the University of Minnesota has mapped the DNA of the cryptosporidium parvum parasite, which can cause veterinary as well as human health problems, and found it has a few tricks that help it evade drugs. “Despite intensive efforts over the past 20 years, there is currently no effective therapy for treating or preventing c. parvum infection in humans,” the researchers wrote in an online advance version of their report in the journal Science. “This is a horrible, hard-to-treat condition, largely because we lack a basic understanding of the genetic makeup of the organism,” Mitchell Abrahamsen, who led the study, added in a statement. Their study shows the parasite is missing many of the structures that current drug therapy targets. Without a target, the drugs are worthless. “We now realize that many of the conventional anti-parasitic drugs that have been used in an attempt to treat infected individuals have failed because the biochemical targets of the drugs are absent in c. parvum,” Mr Abrahamsen added.But they found some genetic weaknesses that could be exploited by drug developers. The weak points look like they were originally plant or bacteria genes, and they might be so different from any human genes that they could safely be targeted by new drugs, they said. Cryptosporidium is spread through feces of infected hosts and causes sometimes severe diarrhea in humans and animals. Most people with healthy immune systems recover after several days of misery. But the very young, very old and those with suppressed immune systems such as AIDS patients can become severely ill and even die. It is also a veterinary problem. Cryptosporidium infection can cause newborn calves to die of diarrhea.(Source: Reuters Health, March 2004)