Injecting tailored bacteria linked to those that causes tuberculosis can protect against the lung disease, found a US study. Tuberculosis is an infectious disease, which typically affects the lungs. It is spread through droplets from the lungs of people with the active form of the disease.
However, in healthy people, infection often does not cause any symptoms. Symptoms of active TB may include chest pains, coughing , weakness, weight loss, fever and night sweats. Tuberculosis is curable with a course of antibiotics. More than nine thousand cases of TB are reported only in the UK each year.
Tuberculosis is occurred due to Mycobacterium tuberculosis. According to estimation by the World Health Organization, TB is one of the top ten foremost causes of death that claims more than one and half millions of lives each year. The BCG vaccine has shown variable consequences.
The BCG vaccine has been shown to be effective by zero and eighty percent in diverse areas of the world. The research team from the Albert Einstein College of Medicine in New York was examining a group of genes known as esx-3, variants of these genes are in all sorts of Mycobacterium and help the bacteria evade the immune system.
Mycobacterium tuberculosis cannot stay alive in the absence of esx-3 genes but its relative, Mycobacterium smegmatis, can survive without esx-3 genes. In lab mouse researchers deleted the genes from Mycobacterium smegmatis and administered otherwise lethal dose to the mouse. Within three days the mouse had cleared the bacteria from the lungs and kidneys.
Then researchers attempted putting the esx-3 genes from Mycobacterium tuberculosis into Mycobacterium smegmatis, the process is called as Ikeplus. They found, mice were still capable to quickly clear an Ikeplus infection but it appeared to depart a long-term immunity against Mycobacterium tuberculosis. The mice trails showed that the injections could entirely eradicate tuberculosis bacteria in some cases.
Mice those contaminated with the TB bacteria and did not receive any vaccine died after fifty-five days on an average. While, those vaccinated with BCG died after sixty-five, but mice immunized with Ikeplus survived for one hundred and thirty-five days. Mice those survived more than two hundred days, researchers were no longer found the lethal bacteria.
According to study author Prof William Jacobs they again and again protected mice better with Ikeplus than with BCG. This is something they have reverie about for years, to be able to get longer protection and bactericidal immunity. Only twenty percent of mice were long-term survivor so the vaccine would require further development.
source : http://www.bbc.co.uk/news/health