Philip J. Goscienski, M.D.
When antibiotics were discovered about 80 years ago they not only transformed medicine, they transformed humanity. It is no exaggeration that this class of chemicals has saved billions of lives. Scourges that ranged from pneumonia to plague, rheumatic fever to tuberculosis have dramatically declined, some nearly vanished. Sensitive bacteria succumbed to antibiotics but the few that survived have risen up to threaten us again. Some scientists fear that a generation from now mankind will face infectious diseases that will be nearly impossible to control.
When penicillin came into wide use in the late 1940s it didn't take long before some strains of Staphylococcus, one of the chief causes of disease at the time, emerged unscathed after a course of treatment. If only a single bacterium out of trillions is able to mutate into a resistant form it is able to reproduce unchallenged until a newer, more potent antibiotic is available.
Antibiotics work primarily by interfering with the chemistry of the bacterial cell. If some of those bacteria possess an alternative chemical pathway that can bypass the vulnerable site where the antibiotic works, they will survive. Their descendants will also have the ability to evade the lethal effect of the antibiotic.
Bacteria don't become "immune" to an antibiotic. The proper term is resistant, although the media still use the former term inappropriately.
Some bacteria are able to transfer genetic material that carries the antibiotic-evading capability to other species. This is especially likely to occur within the intestines of animals and humans where several thousand different species can coexist and share such resistance.
Some bacteria have become resistant to several antibiotics, a few to every known antibiotic. In the past the biggest threat occurred in hospitals, where antibiotics of several types are used frequently, both to treat infections and to prevent them. These multiply resistant strains are now emerging in the community. One of the most dangerous is Methicillin Resistant Staphylococcus aureus (MRSA).
As we age our immune system becomes less effective; the very young have immature immune systems. That explains why the very young and the very old are more likely to die from Salmonella infection, usually a non-fatal food-borne illness.
As antibiotics lose their effectiveness it's more important than ever to avoid infection. Frequent handwashing prevents the spread of disease; a healthy diet and regular physical activity boost the immune system. And be sure to get your flu shot.
Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at firstname.lastname@example.org.