I’ve written here before about the phenomenon of antibiotic resistance in bacteria, resulting from the indiscriminate use of antibiotics and other anti-bacterial agents. Although the development and use of antibiotics has been a great medical advance, and has saved many lives, it is nonetheless clear, from an evolutionary perspective, that using antibiotics creates selection pressure for resistance to those drugs.
The “Short Sharp Science” blog at the New Scientist has an article describing one of the most worrying developments yet in the emergence of resistant bacteria. In a study [abstract] published in The Lancet Infectious Diseases, researchers examined the prevalence of a bacterial gene, called New Delhi metallo-β-lactamase 1, or NDM-1, which confers resistance to a broad array of antibiotics. The study found some disturbing things:
- The gene, which was initially detected in bacteria in India, appears to be spreading relatively rapidly to other parts of the world, due to global travel, particularly so-called “medical tourism” in which Western patients travel to Asia for cheap surgery.
- In addition to conferring resistance to “everyday” antibiotics like penicillin, the gene also produces resistance to a class of antibiotics called carbapenems, which have been used as the “last resort” for treating infections resistant to ordinary antibiotics.
- The gene can be passed relatively easily among different bacteria.
This combination of characteristics could make this a very nasty problem. The New York Times also has an article on the discoveries.
Also worrying was that the gene [NDM-1] was found on plasmids — bits of mobile DNA that can jump easily from one bacteria strain to another. And it is found in gram-negative bacteria, for which not many new antibiotics are being developed.
While I think some of the apocalyptic predictions are somewhat overblown — as the Times article points out, highly-resistant organisms have emerged and been dealt with before — this should be another reminder that sloppy medical practice in using antibiotics can have real negative consequences.