In November, a study based in China discovered that bacteria have started to become resistant to our “last resort” antibiotics. Antibiotics work by disrupting the systems of a bacteria, which kills the bacteria or prevents its reproduction in the process. Due to natural selection, random mutations over time can give bacteria a natural resistance to the methods that these antibiotics use. This has been occurring since the discovery of penicillin’s bacteria fighting capabilities in the 1930s. Since penicillin, many different antibiotics have been discovered and used to treat infections.
Back in 2012, the antibiotic called colistin was deemed to be important by the World Health Organization. It was the last antibiotic that every bacteria was still susceptible to. This study from mid-November confirmed that at least one strain of E. coli has developed the first mechanism to resist colistin. This mechanism is a gene called MCR-1. MCR-1 has been shown to have the ability to transfer between bacteria, which indicates that it will spread quickly. The study from China showed that between 15 and 21 percent of samples tested positive for MCR-1. The study found that MCR-1 has shown up in 16 human samples so far.
On December 5, 2015, the MCR-1 gene was detected in a patient in Denmark. It has taken a month for the superbug to travel from China to Europe, and it will not be long until it has spread across the globe. At this point, the bacteria with the gene are rare. However, as time goes on, more and more bacteria will be resistant. This will happen more quickly as long as colistin is used so heavily in farming. Studies have shown that the gene remains in bacteria even when unused, which indicates that MCR-1 and its ability to cause resistance to colistin will not be leaving anytime soon.