Diarrhea disorder Giardiasis caused by two different parasite species

Aug 21, 2009

(PhysOrg.com) -- Researchers from Uppsala University and the Karolinska Institute have found major genetic differences between the human variants of the intestinal parasite Giardia intestinalis. Sequencing of the genomes using the latest technologies shows that people are infected by two different Giardia species, according to a study published in the journal PLoS Pathogens today.

Giardia intestinalis causes 250 million cases in humans (Giardiasis) every year and a huge number of animals infections, but little is known about the disease. It is known that there are seven main genetic groups (A-G) of the parasite. New research indicates that the different variants can infect different hosts and lead to different symptoms.

Variants A and B can infect humans, and B is the most common in humans. The scientists sequenced the genome of a B parasite that has been used in experimental infections and compared that genome with a previously sequenced A variant. Major genetic differences were identified, above all in that are important for avoiding the immune defense system. Certain genes are specific to the respective variants, and differences have been found in most of the proteins in the variants. The differences are so great that the variants can be different species.

"The identification of such major genetic differences between Giardia that infect humans changes how we regard the infection. This will be of great importance for the development of new methods for the diagnosis and treatment of Giardiasis," says Professor Staffan Svärd at the Department of Cell and Molecular Biology, Uppsala University.

Provided by Uppsala University (news : web)

Explore further: Sugar mimics guide stem cells toward neural fate

add to favorites email to friend print save as pdf

Related Stories

Giardia genome unlocked

Sep 27, 2007

Giardia lamblia, one of the most common human parasites in the United States, causes more than 20,000 intestinal infections a year, often through contact with contaminated drinking or swimming water. In the September 28 iss ...

Johns Hopkins to participate in 1000 Genomes Project

Jan 22, 2008

Researchers at the McKusick-Nathans Institute of Genetic Medicine (IGM) at Johns Hopkins will join other national and international scientists in the 1000 Genomes Project, an ambitious effort that will involve sequencing ...

Humans and chimpanzees, how similar are we?

Nov 20, 2006

The DNA sequences of humans and chimpanzees are 98.5 percent identical, but now Uppsala University researchers can show that parts of the genetic material are missing in one species or the other.

Cataloging the structural variations in human genetics

May 09, 2007

A major new effort to uncover the medium- and large-scale genetic differences between humans may soon reveal DNA sequences that contribute to a wide range of diseases, according to a paper by Howard Hughes Medical Institute ...

Genetic differences help protect against cervical cancer

Mar 12, 2009

Women with certain gene variations appear to be protected against cervical cancer, according to a study led by scientists at Albert Einstein College of Medicine of Yeshiva University and reported in Clinical Cancer Research. Knowi ...

Recommended for you

Sugar mimics guide stem cells toward neural fate

Jul 30, 2014

Embryonic stem cells can develop into a multitude of cells types. Researchers would like to understand how to channel that development into the specific types of mature cells that make up the organs and other structures of ...

Researchers uncover secrets of internal cell fine-tuning

Jul 29, 2014

New research from scientists at the University of Kent has shown for the first time how the structures inside cells are regulated – a breakthrough that could have a major impact on cancer therapy development.

User comments : 0