By Janet Fang
Posting in Environment
Bacteria have been popping up with the ability to resist our drugs for decades. Now, 30,000-year-old soil shows that they've have the genes for resistance long before we were a problem for them.
Wait a minute… resistance to antibiotics came before antibiotics? That’s right, a new study of 30,000-year-old bacteria shows.
In particular, genes for antibiotic resistance are a natural phenomenon that predate modern antibiotic use for human diseases, and all the survival pressures that exerts on bacteria.
With few new wonder drugs in the pipeline, some doctors are warning of a postantibiotic age, as ScienceNOW calls it, in which simple infections will become untreatable again. All of this led us to think that superbugdom is a modern thing.
Alas no. A team led by Hendrik Poinar and Gerard Wright of McMaster University in Hamilton, Ontario, drilled cores from in 30,000-year-old Beringina permafrost – that is, in frozen, pristine soil from the Yukon Territories alongside mammoths.
- After extracting ancient bacterial DNA samples from the permafrost, they found genes that confer resistance to antibiotics such as penicillin, tetracycline, and vancomycin.
- Focusing on one of the genes, they found that the resistance to vancomycin – significant clinical problem since 1980s that continues to cause outbreaks of hospital-acquired infections worldwide – is similar in activity and structure to modern variants of superbugs.
The genes were just as effective in the Pleistocene, and they look just like the ones that exist now, Wright says. “That tells us that resistance is old and pervasive in the environment.”
So the big question, Wright asks, is where does all of this resistance come from?
Researchers suspect that natural antibiotics have been around as early as 40 million years ago. “These organisms are living in a pretty hostile place,” Wright explains. They are under a constant barrage of antimicrobial chemicals produced by fungi, plants, invertebrates, and other bacteria. “They pretty much had to develop resistance just to live where they live.”
So, was the war between germs and modern medicine all in our head?
"Antibiotics are part of the natural ecology of the planet so when we think that we have developed some drug that won't be susceptible to resistance or some new thing to use in medicine, we are completely kidding ourselves,” Wright says. “Microorganisms have figured out a way of how to get around them well before we even figured out how to use them."
No antibiotic can last forever, Wright continues, and “we should not think of them as wonder drugs but as really special resources.”
The study was published in Nature today.
Image of penicillin via Wikimedia
Aug 31, 2011