How to differentiate between a viral or bacterial infection.

I know I had mentioned most of my blog posts from now on would regard tuberculosis topics. However, this new post caught my attention while researching. As the oldest of seven, I have always heard my mom complain about the doctor prognosis when she took her kids in due to high fevers or vomit. What was annoying to her was that every time she went, the doctors would say it was a virus. However, viral infections usually require a long series of blood work to determine if a pathogen is present. They could have never correctly diagnosed her with that after a few mouth, ear and eye examinations! Well, this article posted on the Science Daily website described the discovery of a Real-Time PCR method that can help establish a diagnosis of a viral infection versus a bacterial infection.

Since the method involves PRC it must indicate that there is some kind of genetic information being processed for this diagnosis, right?  Indeed, the differing immune system responses between a viral infection and a bacterial infection lies at the genetic level where certain genes are turned on during a viral attack and leave a fingerprint that can identify the pathogen to be blamed ^[1]. Because of this, this new method can be applied and in a trial run showed a high accuracy of differentiating between a viral and bacterial infection. Researchers controlled this experiment by analyzing the samples of individuals carrying specific infections. The scientists indicate that this method can work even when the pathogen guilty of infection is unknown, unlike in previous blood test work.

Even though the trial did not use an extensive amount of individuals, and the test is currently taking 12 hours to complete ^[1], it is a method we cannot take our sights off of. More trails and validation tests are still to be done so they can bring great benefit to the rapid and correct diagnosis of infections. This however, has me wondering if this method can be used to diagnose tuberculosis at a faster rate. Presently, a TB test usually takes about 2-3 days and sometimes even more tests are required for its diagnosis. A 12 hour window definitely beats that amount of days! And because a major problem in the resistance of TB treatment is the delay between suspecting you have it and confirming it ^[2], this could greatly help prescribe treatments that are more appropriate for any infection. Would you be willing to give this new method a try or continue taking the diagnosis doctors give you on a rapid examination?  

Reference:

[1] Duke Medicine (2013, September 18). Genomic test accurately sorts viral vs bacterial infections.ScienceDaily. Retrieved September 20, 2013, from http://www.sciencedaily.com/releases/2013/09/130918143305.htm?utm_source=twitterfeed&utm_medium=twitter&utm_campaign=Feed%3A+sciencedaily%2Fmost_popular+%28ScienceDaily%3A+Most+Popular+News%29

Where does Tuberculosis (TB) come from?

When my younger sister, now 16, was diagnosed with TB I was shocked. I knew that for school most students needed to get tested in order to avoid transmitting this disease to others, however, I did not really ever think about people having this disease dormant in them. I always figured people would get TB from an infected individual that was previously infected and so on. However, the dormancy of this disease in my sister caught my attention. Does it mean she was born with it? I don’t know. But I feel like this just might be the topic I need to look into for my term paper. So to start off, there was an interesting post I read on m.phys.org about an article that was published on the journal Nature Genetics in which the origin of Tuberculosis was discussed.

[1] M. tuberculosis bacterial colonies. Image credit: Centers for Disease Control and Prevention.

At the beginning of my search I was not aware of the amount of deaths caused by TB but I now know that it is one of the deadliest diseases of humans, causing 1-2 million deaths per year mostly in developing countries. But where did it come from? An international group of researchers led by evolutionary biologist, Sebastein Gagneux from the Swill Tropical and Public Health Institute, found the answer to this question after using whole-genome sequencing of 259 Mycobacterium tuberculosis strains collected from different parts of the world. They were able to construct the genetic pedigree of this bacterium and trace its origins back at least 70,000 years ago in Africa! The researchers also compared the genetic evolutionary trees from mycobateria to the ones of humans and found that both have a very close relationship because of the high number of similarities. These similarities indicate that both human and TB bacteria emerged and migrated out of Africa. In addition, the expansion of human populations living in large groups of people and the changes in lifestyles may have created a perfect environment for the transmission of the disease. The researcher’s results also depict that TB could not have been transmitted from domesticated animals as previously thought since, “Mycobacterium tuberculosis emerged way long before human started domesticating animals” [1].

Additional articles I've come across indicate the high resistance to treatment by Mycobacterium but I will discuss some of them later. However, the discovery of the evolutionary paths of both humans and TB after the experiments of these researchers can help possibly determine future paths the disease might take. This in turn could aid in the production of new disease control measures and new medication advancements for its treatment. If you all know a little bit more about TB I would love to hear your thoughts. I know I will still research the dormancy of TB in people and try to figure out how it was my sister contracted this disease.

Reference:

[1] Mycobacterium tuberculosis: Our African follower for over 70,000 years. Phys Org. September, 1, 2013. http://phys.org/news/2013-09-mycobacterium-tuberculosis-african-years.html

Revelations of Molecular Damage by Antibodies in Human Cells

Rare side effects of prescription drugs have always been annoyingly and rapidly advertised at the end of media commercials. Even prescribed antibiotics give the warning labels of such effects but never did I think these side effects occurred at the molecular level! Recently, I came across an article from the Wyss Institute for Biological Inspired Engineering at Harvard University where two methods to avert the harmful side effects of long-term antibiotic treatment were discussed after biochemical tests confirmed the damage antibodies cause to human cells.

Antibiotics cause oxidative stress in cells, which leads to cellular damage. For example, in healthy cells (left), mitochondria, which are labeled yellow here, are long and highly branched. But in cells treated with the antibiotic ciprofloxacin (right), mitochondria are abnormally short and unbranched, and they do not function as well. Image credit: Sameer Kalghatgi and Catherine S. Spina [1].

Doctors usually prescribe antibiotics with the false impression that it will kill bacteria and leave the human cells and tissues unharmed. However, over the years continual occurrences of people experiencing these commonly warned side effects led scientists to analyze the underlying factor of such effects. A group of scientists led by Jim Collins from the Wyss Institute had already determined that antibiotics kill by bacteria by a process called oxidative stress. This is “a condition in which cells reproduce chemically reactive oxygen molecules that damage the bacteria’s DNA and enzymes, as well as the membrane that encloses the cell [1].” However, after several biochemical tests, this oxidative stress was found to damage the DNA, proteins, lipids and mitochondrial functionality in human cultured cells after pro-longed use of antibiotics. Clinically, this gives a desperate call for a way to counteract the effects of oxidative stress but this team of scientists has found it! The scientists suggest that using an antibiotic that stops the reproduction of bacteria will reduce the need for a huge amount of reactive oxygen production therefore lessening the effects of oxidative stress. Also, they indicate that using antioxidants would be a good way to flush out already produced reactive oxygen. Since the two methods they have indicated include FDA-approved reagents this solution is eagerly awaiting clinical use.

Do you believe more trials other than the ones mentioned in this article need to be produced in order to analyze the effectiveness of the suggested solution before putting it out in the clinical market?  I think that because the pharmaceutical industry hasn't done enough to do away with all the common health side effects of antibiotics and/or medicines, this method of reducing oxidative stress should be put to use immediately. However, I ponder if after all the mitochondrial damage has occurred, there are effective methods of retroactively alleviating the damage. I would love to hear your thoughts about this topic!

Here's is the link to the article:

[1] Dodging antibiotic side effects. Ferber, Dan. Wyss Institute for Biologically Inspired Engineering at Harvard University. July3, 2013. http://wyss.harvard.edu/viewpressrelease/117/