genetic modification

Melioidosis is a deadly tropical disease that flies under the radar. Around 150-200 thousand people get it every year, and more than half of people diagnosed die. One of the largest problems of this disease is that it takes several days to diagnose, meaning it takes several days for patients to receive the correct treatments. However, a new test, using CRISPR, could change that.

A new test has been invented that uses CRISPR to detect a genetic target that is specific to Burkholderia pseudomallei, which is the bacteria that causes meliondosis. The new test can detect the gene with almost a 94% sensitivity. It was developed by researchers at the Mahidol-Oxford Tropical Medicine Research Unit, Chiang Mai University, Vidyasirimedhi Institute of Science and Technology in Thailand, and the Wellcome Sanger Institute in the UK. The results of this new CRISPR test mean that thousands of people could be saved annually from meliondosis, with an easy to use rapid test.

The disease is caused by Burkholderia pseudomallei, which is found in water and soil of sub tropical and tropical regions. It enters the body through cuts on the skin, ingestion, or inhalation. One of the reasons it’s difficult to diagnose is that the symptoms range from pneumonia to those of a chronic infection. This, paired with the fact its more common in rural areas, causes this disease to be under reported.

Currently, melioidosis is diagnosed in patients after bacterial samples are cultured, which takes three to four days. But, in Thailand, 40% of patients die after just a couple days while waiting for the tests to come back. Currently, there is no vaccine for this disease, but it can be treated with an antibiotic such as carbapenem. However, due to the range of the symptoms, many other and or wrong antibiotics are prescribed, which wastes time and money.

To develop a new test, researchers identified a genetic target specific to B. pseudomallei by analyzing over 3,000 B. pseudomalleigenomes. Their new test called CRISPR-BP34, ruptures bacterial cells and using a recombinase polymerase amplification reaction to amplify the bacterial target DNA for increased sensitivity. In addition to this, a CRISPR reaction is used to provide specifics. The researchers collected samples from about 100 people with the disease and 200 without, in order to test the legitimacy of the test. The new test got results in just four hours and enhanced the sensitivity from about 66% to almost 94%.

This relates to our study of the immune system in AP Biology. As we’ve learned in Biology, first macrophages and neutrophils are the first responders, and they attempt to engulf and destroy the disease. The helper T-cells try and coordinate the response while killer T-cells are attempting to destroy the disease. And cytokines signal molecules to come help defeat the disease. While these attempts by our body is unsuccessful more often than not, it still displays the immune system response learned in AP Biology.

This new test will help save thousands of lives by making diagnoses faster, which will allow the correct treatment to be given in hours, instead of days. This is truly a groundbreaking invention.

Where else do you think CRISPR can be used?

Had you ever heard of Melioidosis before?

Why do you think there is such a large range of symptoms for Melioidosis?

Since the discovery of CRISPR-Cas9 system (Clustered Regularly Interspaced Short Palindromic Repeats), gene editing has become a highly debated topic. One of the reasons backing the use of CRISPR-cas9 is to prevent diseases. These diseases include mosquito-borne diseases such as zika, dengue fever, and malaria. Malaria in particular kills around 3,000 children every year. Various groups of scientists have worked on genetically modifying mosquitos to stop the spread of malaria by making female offspring sterile and unable to bite, making male offspring sterile, or making mosquitos resistant to carrying diseases. A point of concern was if the modified gene would stay relative and would carry from generations. In order to make offspring, genes from both parents must be used, resulting in the offspring carrying the modified gene only half the time. In particular cases, mutations would occur in the altered DNA, which nullified the genetic changes. This has been solved by developing a gene drive, which makes the desired gene dominant and occur in the offspring almost 100% of time. This entails almost the entire mosquito population could have this modified gene in as little as 11 generations.

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Recently, the government of Burkina Faso, a small land-locked nation in west Africa, has approved for scientists to release mosquitos that are genetically modified anytime this year or next year. The particular group of mosquitos to be released first is a group of sterile males, which would die rather quickly. Scientists want to test the impact of releasing a genetically modified eukaryotic organism in the Africa. It is the first step in “Target Malaria” project to rid the region of malaria once and for all.

One of the major challenges in gaining allowance to release the genetically modified species was the approval of the residences, who lack words in the local language to describe genetics or gene editing. Lea Pare, who leads a team of scientists modifying mosquitos, is working with linguists to answer questions the locals may have and tp help develop vocabulary to describe this complex scientific process.

What do you think about gene editing to possibly save millions?

Read the original article here.

View a video explaining how scientists can use genetic engineering to fight disease here.

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: genetic modification

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