The Black Plague that rampaged across Europe and Asia in throughout the 14th century has reared its ugly head again, except this time we are much better equipped to fight it with the advent of antibiotics. The plague never truly disappeared completely as there have been a fair few cases of the plague surfacing in the United States as well as other countries throughout history.
While no longer a death sentence, the plague still has the ability to cause untold pain and suffering on an individual that is infected with it and not treated immediately. The main fear is that a superior strain of the bacteria will mutate that is resistant to known and widely used antibiotics. According to an article by The Guardian, back in 2007, a resistant strain of the plague had been found. This specific strain was able to resist the effects of eight major antibiotics raising fears of another devastating pandemic. A NIAID article gave me insight into how bacteria become resistant to antibiotics. The main cause would be mutations in a bacteria that cause it to be able to survive exposure to the an antibiotic. There are also a few ways that misuse of these drugs can cause much bigger problems in the future. The use of antibiotics in agriculture has lead to many a resistant disease due to feeding mass quantities of antibiotics to cattle and other animals in an attempt to prevent disease in the first place. All that this really does is make a perfect breeding ground for resistant diseases. There are also cases where medical staff and professionals will give antibiotics to patients that have a viral infection to placate the patients. These are numerous reasons that infectious and deadly diseases from the past are still a danger today.
The Decameron http://pinkmonkey.com/dl/library1/b1.pdf