When thinking about evolution, most people often think of plants and animals and their physical changes over many generations. However, people often forget about the evolution of bacteria and other pathogens that is now severely affecting the efficiency of our modern day drugs. Tuberculosis is a bacterial infection, involving the lungs but can spread to other parts of the body, that has been around for thousands of years. The genome involved with the disease is 110 M. tuberculosis. The article states that the sequencing of this genome has revealed that the bacteria has undergone many mutations over the generations. Over time, the bacteria has been able to evolve in order to survive. For instance, strains of tuberculosis have become resistant to our antibiotics and are known as MDR (multidrug resistant tuberculosis).
The article also discusses the expansion of the bacteria during urbanizing pressures of the Industrial Revolution, the devastation of World War I, the outbreak of HIV, and now during the rise of multidrug resistance. Additionally, Dr. Pepperell mentions that without an ancient DNA study, it is very difficult to estimate exactly how long ago tuberculosis emerged. The scientist conducted a survey of the single lineage of tuberculosis and found that with such a large sample size and one-hundred and ten full genomes presented, the evolutionary pressures driving the genetic changes can be analyzed. Over six thousand sites were examined, and about one hundred were under positive selection and fifteen were not even associated with antibiotic resistance. It is important, based on these findings, to realize that many mutations of the bacteria don't coincide with its linkage to multidrug resistance; however, the fact that many of the vaccines and antibiotics that are used to treat and prevent tuberculosis aren't affecting the bacteria's population is devastating for our trust in modern medicine and our sense of security when it comes to our health.
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ReplyDeleteI found your summary very interesting, especially because we oftentimes associate mutations and evolution to animals rather than diseases. It is important for us to keep in mind that just as animals demonstrate natural selection and evolution, disease-causing cells do the same.
ReplyDeleteIt was interesting to learn how the tuberculosis strain has mutated several times over the years. It certainly makes it more difficult to constantly develop vaccines and antibiotics to combat the disease as the naturally selected tuberculosis strains would resist the drugs, creating a need to make stronger drugs.
ReplyDeleteWe are finding this a lot more now. Make sure you take all of your antibiotics because a lot of viruses are becoming resistant to the drugs.
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