The Killers Within: The Deadly Rise of Drug Resistant Bacteria
Book by Michael Shnayerson and Mark J. Plotkin
This is a good book to read now especially with the current coronavirus that is spreading across the globe.
It was front page news when drug resistant bacteria invaded BC Childrens Hospital’s intensive care nursery. But the hundreds of thousands of drug resistant staph infections which occur annually in hospitals throughout the world never make it into the paper. Yet these infections can make routine surgery and hospital stays dangerous and unpredictable one patient at a time.
For three and a half billion years bacteria have been adapting to unforgiving environments ranging from our stomachs to boiling hot outflows miles under the ocean. Antibiotics have been used for a little more than sixty years. Antibiotic resistant bacteria are disappointing and frightening; but the resistance is not surprising.
The Killers Within is a well researched, engagingly written book detailing the worldwide rise of multi-drug resistant bacteria in hospitals and in the community. The rapid evolution of toxic bacteria –Streptococcus pneumoniae, Enterococcus faecium, Staphylococcus aureus among others – is a deadly but fascinating tale of adaptation.
Twenty years ago infections like staph were routinely eliminated with inexpensive, very effective, antibiotics. Now many of these infections are multi-drug resistant and, if they can be beaten at all, require new, expensive and often toxic drugs. At least 40,000 Americans die each year as a result of drug resistant bacterial infections. That number is growing.
Over prescription of antibiotics, patients’ failure to follow the full course of antibiotics prescribed, the use of antibiotics as “growth promoters” in the cattle, swine and poultry industries have all contributed to resistance. Resistant strains spread in hospitals because health care workers don’t wash their hands between patients or because the bugs survive on not quite sterile instruments, catheters and bed sheets.
The immediate causes of drug resistant bacteria are important but The Killers Within makes a larger point. Bacteria’s ability to rapidly evolve under pressure suggests that antibiotics’ astonishing success over the last sixty years has been illusorily.
The discovery of penicillin followed by the broad range of antibiotics created an evolutionary bottleneck for bacteria populations. For a few years a drug would kill almost all the target bacteria. The key word here being “almost”: with every drug a few bacteria survive. These survivors are slightly more resistant to the drug and this slightly resistant population is the only one which breeds.
Bacteria generations are measured in hours so evolution is fast. Drug resistance rises and is encoded genetically. In a single decade “bacteria reproduced 50,000 times, trying each time, in some soulless but utterly determined, Darwinian way, to adapt in order to prevail.”
Drug strategies which did not take bacteria’s rapid evolution into account were doomed to fail eventually.
In Nature bacteria do not multiply unchecked. There are a variety of natural anti-bacterials: frog peptides and Komodo dragon saliva kill bacteria very efficiently. Synthesizing these natural anti-bacterials promises highly effective anti-bacterials in the future. Vaccines, naturally occurring or genetically engineered also hold some future hope.
For the moment, the authors see the most promising approach as weird little viruses called phages. Every bacteria seems to have a phage which has co-evolved specifically to feast on that particular bacteria. Phages inject their DNA directly into a bacteria. This DNA takes charge of the bacteria and forces it to make more phages instead of more bacteria before it dies. These daughter phages go and colonize more bacteria.
The anti bacterial action of phages was discovered by a French Canadian named Felix d’Herelle around 1915. He published his results in 1917 to the amazement and frank incredulity of the scientific world.
d’Herelle’s work was largely ignored in the West, particularly after the discovery of penicillin, but continued behind the Iron Curtain at the Eliava Institute in Tbilisi, Georgia. Hundreds of different bacterial strains had their phages discovered and catalogued at the Institute which is still in operation.
Phages offer a more sophisticated ecological strategy for bacteria control. They only have the capacity to commandeer their particular bacterial cell and are unable to attack other species of bacteria or human cells. And phages are likely to mutate right along with bacteria as they have been doing through the whole of geologic time.
For the last sixty years we have used a single approach to anti-bacterial warfare: antibiotics. The Killers Within details the tragic but inevitable failure of that approach. Antibiotics have bought us is a little time to invent new ways of dealing with the ecology of bacteria. But that time is fast running out.