A Cure Found For the Disease Giardiasis

If you recently went to a different country and are finding yourself having the following symptoms:
*projectile vomiting

* roaring flatulence
* sulfurous belching
* explosive diarrhea.
You are under the attack of giardiasis, a form of suffering devised by the single-celled parasite known as giardia. http://www.nytimes.com/2008/12/16/science/16giar.html?_r=1&ref=science writes an article about this parasite. Giardiasis can linger onto you for months, because the parasite is able to play a defense against the immune system. The giardia has 190 coats. As the giardia “activates” one coat, the immune system is getting its army of antibodies ready. Once the immune system has generated antibodies against one coat, the parasite switches to another coat. There are some two-hundred eighty cases of giardiasis in the world because of the parasite’s persistence and infectivity.

However, there is a noxious weakness in the giardia’s game of switching coats. Biologists at the Catholic University of Córdoba in Argentina led by Dr. Lujan have found a way to stop the parasite. Their cunning counter play is to make the parasite wear all of its coat “proteins” at the same time. This change in the parasite should serve as the perfect vaccine, because it immunizes the body to the full repertoire of giardia’s coat proteins all at once. This vaccine may also help in producing vaccines against any other single-celled parasites that play the game of coat switching to dodge the immune system. For example, malaria causes sleeping sickness and Leishmanias.

The biologists were able to identify the mechanism by which the parasite controls its coat proteins. Each of the parasite’s 190 coat genes is the recipe for making a different protein. To produce the coat, giardia does not switch these genes on one at a time. Instead, it leaves them all “turned” on, allowing each gene to generate into a messenger RNA (Ribonucleic Acid) copy of itself. The synthesis of proteins would usually be directed by messenger RNAs, but all of the messengers get destroyed by giardia except one which makes the coat of the day. To kill the other messenger RNAs, giardia has adapted an ancient cellular system known as RNA interference. The system is designed to destroy foreign RNA, like invading viruses. Dr.Lujan, a biologist said and I quote, “………so it was surprising to find it regulating a cell’s own RNAs”. Dr. Lujan believes this is the case. He proved his theory by disrupting giardia’s production of enzymes, which are components of the RNA interference system. He also said and I quote, “I did not yet know how the organism shifted between coats but suspected that the RNA interference system favored whichever messenger RNA happened to be the most abundant at the time, and destroyed all others.”

My opinion on this subject is that it is fascinating. Dr.Lujan and his team have made a great discovery. This discovery can be used to determine more about single-celled parasites. What’s really interesting about giardia is that it is an ancient type of eukaryote. At the end of the article, they write about the parasite. I learned three facts that I didn’t know before. One fact is that this parasite was one of the earliest branches of the eukaryotes. Another fact is that giardia lacks mitochondria, which is an organelle that every eukaryote has. The last fact is that it has two nuclei, while a normal eukaryote has one. Hence, I think that this article was very interesting.