For a period of time in recent history, antibiotics were heralded as being the most effective possible treatment for infectious diseases. Most of those illnesses were caused by bacterial agents, so the use of medications that killed off harmful bacteria was a sensible, practical solution. However, there is no clear indication that anyone within the medical or scientific communities saw the rapid evolution of antibiotic resistance coming. Even if someone did, history certainly doesn't reflect it all that well. Regardless of the slip-up of the past, it is now understood that the typical antibiotic has a limited lifespan now, being rendered nearly useless as soon as the bacterial agent they target has developed resistance to their effects. This was the case with tuberculosis, which was once thought to have been wiped out in the developed world, and is the case with many other bacterial infections.
The problem of dealing with antibiotic resistance is a complex one. Some bacterial agents have developed their resistance only to certain agents – though those agents are the ones that are prescribed as treatment. Other microbes, on the other hand, have developed effective antibiotic resistance to all antimicrobial agents currently available on the market. This situation, some public health officials worry, is bound to cause major problems. A number of experts are pointing out the gradual increase in the number of resistant cases of tuberculosis to be an indication of the possible damage this problem can cause. With tuberculosis being resistant to all the current drugs used against it, treatment for patients with the resistant strain is becoming more and more difficult, and the disease is becoming more and more fatal.
One single illness that has antibiotic resistance does not a major public health problem make. Most authorities in the medical field would not be worried if there wasn't evidence that other bacterial infections are starting to prove as resilient as the common cold. The common cold has long been a problem for medicine, such that being able to develop a cure for it has long been considered impossible. The bacteria at the root of the cold adapts with a rapid pace, becoming resistant to the effects of medication used to treat it the year before. While hardly something that is life-threatening, there is a very strong possibility that other, more dangerous bacterial agents might emerge with the same level of adaptability. Another possible scenario involves multiple bacterial agents developing resistance and reemerging into the public arena. Their infectious nature and antibiotic resistance, plus the relative degree of congestion in the average urban area, nearly guarantees a rapid spread of infection.
If this sounds like a bad plot for a doomsday scenario in a science fiction novel, that's because said scenarios may not really be that far off the mark. Bacterial adaptation against countermeasures being used against them is at a much faster rate than how fast researchers can develop new antibiotic medication. For example, a hospital in Switzerland found that, within a period of three years, the strains of Escherichia coli that they encountered developed resistance to all five known types of antibacterial agents for it. They have also noted that this sudden increase in resistance was linked to the increased use of said antimicrobial agents, which has caused some to believe that the very success and widespread use of antibiotics is the root cause of the problem. The more bacteria are exposed to the medication, the higher the chances that a mutated strain will emerge that is resistant to the effects.