Fluorescent Protein allows Rapid Identification of Tuberculosis Infection

Tuberculosis is a highly contagious disease of the respiratory system. It is caused by bacteria that becomes airborne when an infected person coughs or sneezes.  Many people who contract the disease have little or no after effects. The disease does have the capability of becoming dormant and reappearing years later.

People who have weakened immune systems, the elderly and infants are more susceptible to tuberculosis than healthy adults. People who work in the healthcare industry, such as nurses and primary caregivers are also at a higher risk of exposure and possible infection.

Pulmonary tuberculosis is spread when a healthy person breathes in airborne bacteria. If they are in close proximity to an infected individual who sneezes or coughs, they may breathe in the bacteria and contract the disease. Symptoms can include fatigue, chest pain, difficulty breathing, cough and an unintentional weight loss. As the disease progresses, swollen lymph nodes may appear in the neck along with wheezing and crackling sounds during breathing.

Chest x-rays, CT scans and a topical TB test may be performed to determine if an individual has been exposed or may have contracted the disease. Because it is highly contagious, a person may be isolated until results are known.

Green fluorescent protein is currently being used to locate and determine the rate of growth of tubercular cells within the lungs and airways. GFP obtained from a specific type of jelly fish does not require cofactors to increase its fluorescent properties. Because of this unique ability it makes an excellent indicator to determine if tubercular cells are present. It is able to show the cell’s location, the degree of replication and toxicity levels. 

Because of the fluorescent nature of the protein, it is easily picked up by imaging equipment and can be measured to show the extent of infection. Another frequently used indicator is DsRed which is derived from coral. Both are excellent indicators, but DsRed seems to offer better results in long term tests.

Fluorescent agents were used as early as the 1940’s to tag and document the actions of specific types of bacteria within the body. GFP was isolated by researchers in 1960, but was not implemented until almost 35 years later. In 1994, GFP was first used to determine gene expression. Since then, it has been used extensively in reporting the number of bacteria present and their rate of growth. It also denotes their location, as well as the location of substances that promote or increase their growth patterns.