Researchers unearth secrets of giardia parasite

Giardia under the microscope. Suha Al Naimi and Kevin Tyler

Scientists have found that Giardia parasite, which is responsible for one of the world's most common gastric diseases, mimics human cells to break gut cells apart in order to feed on them.

Researchers from the University of East Anglia (UEA) have identified the secrets of giardia which confused scientists for more than 300 years.

The parasite produces two main types of proteins which help it to cut through protective mucus layers in gut walls. It can break links in the cells and easily access the nutrients from them.

The researchers while working with colleagues at the Institute of Infection and Global Health at the University of Liverpool on giardia-infected cultures detected two 'families' of proteins, one of which resembled human protein Tenascins. Tenascin regulates cell adhesion during wound healing and tissue remodeling. It helps cells to break apart when necessary and balances proteins which glue the cells together.

However, the eventually evolved giardia tenascins upset body's balance by preventing the healing process in cell junctions.

Dr. Kevin Tyler from UEA's Norwich Medical School who is the senior author of the study said, "We've discovered an entirely new model for how this disease develops in the gut-which can also explain why in some people the symptoms can be more severe. Because the giardia has broken down the cell barriers and made all the nutrients available, other, opportunistic bacteria can move in to take advantage of these 'ready meals' which can make giardiasis even more severe for some."

Even though giardia is one of the first disease-causing microbes to be visualized in 1681, doctors weren't able to detect the reason for the success of the parasite.

Giardiasis is caused by the intake of contaminated food and water. The parasite attack causes symptoms like diarrhea and stomach pain. Currently, more than 200,000 people are infected with the diseases while around 500,000 new cases are reported each year.

Scientists are studying the ways to neutralize the proteins. This can provide therapy for the illness and can be used to study differences in molecules and parasites. The method can be used in more dangerous bacteria strains.