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Dormant TB Bacteria's Hide-out Found
#1
Rainbow 
Even in the presence of effective treatments for tuberculosis, the threat it possessed was not completely stripped down, thanks to the recurrence of the disease. Patients who had their disease completely cured by medication are found to be the subjects of the same again. This happened either due to the re infection of bacteria, Mycobacterium tuberculosis that causes the disease in most cases, or due to the re activation of the bacteria that are residing dormant inside the human body. Most cases of recurrence are due to the re activation of dormant bacteria inside the body, according to recent studies. But no methods are developed until now, to block this re activation as we did not know the hide outs of the dormant TB bacteria until now. The location of the hide outs of the dormant TB bacteria have been found out in studies conducted by a group of scientists lead by Dr Bikul Das from Departments of Medicine and Pathology at Stanford University.

Bikul Das found out that the dormant TB bacteria are residing in the bone marrow according to the studies published in the Science Translational Medicine journal of January 31. These bacteria are in a non replicating, dormant but viable state. This explains the reason why it can get reactivated.

The discovery of the hide outs of dormant TB bacteria was a result of keen observation of Bikul Das on the bone marrow biopsy results of numerous patients. Planning to proceed with working on bone marrow transplantations, Bikul Das did numerous bone marrow biopsies. The biopsies were mainly done on victims of diseases like kala azar, malaria, tuberculosis etc. In the procedures he also looked for TB bacteria through the Acid Fasting Bacillus (AFB) staining. He noted AFB positive bacteria inside the bone marrow. It was at this point when he got the hypothesis that dormant TB bacteria must be residing in the bone marrow cells. But he was not sure whether they were stem cells or progenitor cells as the biopsies cannot reveal any such data.

The later studies were started by taking bone marrow cells of healthy humans and doing in vitro experiments. These in vitro experiments were to check whether the TB bacteria can occupy the bone marrow cells in the in vitro conditions, so as to give hope to further studies on chances of finding bone marrow cells infected with the bacteria. The in vitro experiments showed positive results. They showed that certain bone marrow cells provided shelter for the TB bacteria. Certain bone marrow mesenchymal stem cells (BMMSC) like the CD 271 showed more chances of permission for entry of TB bacteria. Studies were further conducted in the infected cells. These in vitro infected cells were closely observed for several days after the infection. Then it was found out that the infected TB bacteria multiplied around three to four times after the infection, within three to four days. But it showed no signs of any development ahead, and stayed dormant as itself. These bone marrow mesenchymal stem cells are capable of differentiating into any type of specialized cell in the body. They also found that the bacteria can reside in the bone marrow cells only until it gets differentiated. That means once a bone marrow gets differentiated the viable state of bacteria is lost and it is destroyed. After the in vitro studies experiments were done on mice. Group of mice were introduced to TB bacteria through aerosols, and infecting them with the same. The experiments in mice were aimed at demonstrating the capability of TB bacteria in migrating to the bone marrow cells after infection. This experiment also showed positive results when they examined the bone marrow mesenchymal cells after four weeks of infection. More tests revealed presence of viable TB bacteria in the lung mesenchymal stem cells too. In the next step of the studies they tried to find out whether the dormant bacteria can cause infection or not. For this purpose they took dormant non replicating TB bacteria from the lung mesenchymal stem cells of mice, and introduced into lungs of healthy mice. This also produced positive results when they found lung granulomas in the healthy group of mice who were introduced to the dormant TB bacteria.

Final stages of study were done using samples taken from the Idu Mishimi people, who are a group of tribal people belonging to the Mishimi tribe of Arunachal Pradesh state of India. The samples were of individuals who were successfully treated with using anti TB drugs. For the mentioned, nine people were selected and a control group of strength six was taken beside. While the control group showed no measurable dormant TB bacteria within their bone marrow cells, eight of nine people from the experimental group showed presence of dormant TB bacteria in the CD 271 bone marrow mesenchymal stem cells.

This important discovery will cause a turning point in the treatment of tuberculosis. Until recent, the recurrence of TB was only a quiz that needed to be resolved with many answers to many other questions. The most important of those questions were about the location of the dormant TB bacteria, which has been answered now. This also explains why the treatment of TB is difficult. The bone marrow mesenchymal stem cells provided the TB bacteria protection from the immune system. Inside these bone marrow cells they won’t be exposed to the TB drugs either. This increased the chances of re activation of the bacteria. Speculations that this study provided effective treatments for TB, was ruled out by Dean W.Felsher of Stanford University. He stated that, “Our work is only a basic research and does not provide any therapy for patients with tuberculosis. We do hope that our work will provide potentially new scientific approaches that may lead to new treatments for TB.”

We can expect effective treatments for TB in near future, thanks to this highly relevant study. Treatment for TB which can promise a complete cure and rule out any chances of recurrence of the disease can now be made available.
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#2
TB, Tuberculosis, or MTB is a common, and in most instances a deadly, infectious disease. These are caused by strains of the Mycobacteria which target the lungs but can also be found in other parts of the body. Its bacteria, the M. tuberculosis has this waxy cell coating composed of mycolic acid which makes it difficult for gram staining. That is why Acid Fast Bacillus (AFB) detection is used. It is managed by the WHO-endorsed “DOTS”, a multi-step therapy.

Now like having a tricky mind of its own, knowing that people would find it in lung tissue, phlegm, or blood, it has decided to advance its hide-and-seek methods into less expected areas, like the bone tissue. Not only that it avoids being detected, drugs and our body’s own immune system do not recognize its hiding place as well, allowing it to peacefully breed before lashing out with its self-raised army. That makes it rather advantageous once it goes out into the light and does a reactivation.

“This is a very exciting story,” commented Horacio Frydman, a known microbiologist at the Boston University, who apparently was not involved in the study. He, along with his post doctorate advisor from Princeton University , Nobel Laureate Eric Wieschaus, observed the bacteria Wolbachia and announced a first case of it invading the stem cells of a common fruit fly. “Hitching a ride in cells that are self-renewing is a great strategy for reinfecting tissues in the host,” he went on, “and we always assumed that other bacteria should also be doing the same.”

Such harboring is common since only 90 percent of the TB bacteria are cleared, leaving the 10 percent to go elsewhere. Its latent reservoir was still first discovered by Bikul Das, but happened more than 15 years ago. It was only 4 years ago that he replicated the study together with the Stanford University where they found out the bone marrow area densest with the bacteria and look forward into blocking such interactions.
Lyka Candelario, RN
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Dormant TB Bacteria's Hide-out Found00