Hot on the Trail of the Resistant TB Bug Mycobacterium tuberculosis

kcollins — Fri, 13 May 2011 08:00:00 +0000

Like a detective on the hunt, researcher and Nifty Fifty Speaker Sarah Fortune is trying to figure out how Mycobacterium tuberculosis - the bacterium that causes tuberculosis (TB)
- is able to defend itself so well against drug treatment and the body's immune
system.

The challenge is a daunting one. As much as one-third of the world's population
is infected with Mycobacterium tuberculosis, yet relatively little is known about
how the organism manages to persist for so long, sometimes for decades, in so
many people.

Though tuberculosis can be fatal, in most cases the immune system controls the
acute infection. However, small numbers of the bacteria are often able to fend
off antibiotics and immune attack, and remain in the body to cause recurring
infections years later.

"What we are finding is that we can always kill almost all of the bacteria," says
Sarah, Assistant Professor of Immunology and Infectious Diseases at Harvard
School of Public Health, Harvard Medical School and Brigham and Women's
Hospital."Yet there are always a few bacteria that remain. Whenever we relieve
the stress on them, they come back."

TB can spread from person to person through droplets expelled into the air from
infected respiratory systems. Many healthy people's immune systems can control
the infection so that the illness remains latent, but the risk of developing active
disease climbs enormously among people who have HIV (the AID virus) or other
illnesses that compromise the immune system.

To merely say that the resistant TB bacteria are "hiding" is too simplistic, says
Sarah, who holds a degree in medicine from Columbia University College of
Physicians and Surgeons. "Our research is suggesting that the bacteria, while
in the human body, undergo changes in the sequences and the expression of
their genes and are able to divide and pass those changes down to the next
generation."

What do you find interesting about the field of microbiology and the research that is currently taking place in this field?

Read more about Nifty Fifty Speaker Sarah Fortune here.

Watch more about Mycobacterium tuberculosis from Dr. Fortune below.

kcollins Fri, 05/13/2011 - 04:00

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Nifty Fifty

Mycobacterium tuberculosis

Sarah Fortune

I didn't know that before that one third of the worlds population infected by Mycobacterium tuberculosis. Best of luck Sarah Fortune for your wise step and thank you Joanna Pool for your nice post.

Thanks for writing in!

It sounds like Sarah Fortune's research is a modern presentation of Darwin's 'natural selection' theory by passing down functional mutations to the following generations. I have recently read in an article that the variation in Mycobacterium Tuberclurosis Complex (where mycobacterium tuberclurosis is included) was caused by various elements such as growing human poplation and a decrease in purifying selection (purifying selection being the process of eliminating deleterious mutations). they came to the conclusion that the strains causing TB in people was created by this means over a period of time and might also explain the great functional differences in mycobacterium tuberclurosis that Sarah was talking about. I do however, wonder if considering this knowledge, will we ever be able to really cure TB or simply control it?
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