Back in the 1920s and 1930s, millions of dollars were poured in to the study of bacteriophages – viruses that kill bacteria but are otherwise harmless to humans. Back then, diseases like cholera and dysentery were running rampant throughout the planet, and millions died from those two diseases alone. But then Alexander Fleming discovered the antibiotic properties of penicillin in 1928, and Western medicine dropped bacteriophage study almost en masse to move into the new and sexy world of antibiotics.
Looking back on it now, that was a pretty boneheaded move. The overuse and misapplication of antibiotics has helped to hasten the day when bacteria become resistant to many (if not most) types of antibiotics. You see, not every single bacterium is affected equally by an antibiotic. Some antibiotics merely weaken a bacterium until the antibiotic ceases to be administered. Other bacterium might be completely immune to an antibiotic. Regardless, the important thing is that those bacteria most able to survive against antibiotics are the ones that survive and multiply. And given the short life of bacteria in general, natural selection can work its magic in months or even days, instead of the centuries and millennia that humans tend to associate natural selection with. Staphylococcus aureus is not only one of the most common infections in hospitals, it’s one of the hardiest too, having developed resistance to penicillin as early as 1947. MRSA (methicillin-resistant Staphylococcus aureus) is now considered to be “quite common” in British hospitals. And to show you what a problem its become, MRSA was the cause of 37% of all fatal cases of blood poisoning in the UK in 1999; less than a decade earlier, only 4% of blood poisoning deaths in the UK were caused by MRSA.