A potentially horrifying new gene has been detected in Canada. What makes MCR-1 unusual is it’s resistant to the strongest antibiotics available today.
The gene produces a chemical that makes bacteria resistant to colistin, a powerful antibiotic that has fallen out of favour due to its dangerous side effects. However, it’s still used relatively often as a last-ditch medicine when all other remedies have failed.
Medical professionals are concerned that if the new gene were to manifest itself in forms of bacteria, making it invincible to colistin, patients could find themselves in serious harm.
MCR-1 was first reported in British medical journal The Lancet in November last year, after Chinese scientists discovered a number of samples of the E-coli bacteria containing the MCR-1 gene on meat and hospital patients. They hypothesized the gene came from livestock, as they consume mass quantities of antibiotics to gain weight and prevent illness.
MCR-1 has been detected in bacteria samples gathered across the world, in Asia, Africa and even the UK; these are the first cases discovered in Canada. One came from a patient in Ottawa, and in two samples of ground beef found in Ontario.
The gene is unique, as it’s found on a piece of free-floating DNA called a plasmid, rather than being tethered within a chromosome. This means it can easily be ‘swapped’ between bacteria, allowing them to resist the effects of antibiotics. The antibiotic resistance epidemic is already upon us, and strands like the MCR-1 doesn’t ease tension. Freak bacteria that’ve managed to avoid being killed by antibiotics go on to reproduce and spread – creating new strains that leave current medicines ineffective.
That’s why colistin is still useful: it’s so rarely used, bacteria’s haven’t adapted to become resistant to it. If it were to be used more often, MCR-1 could spell doom for antibiotic medicine’s last defense.
Fortunately, no deaths caused by MCR-1 have been reported, but if the gene becomes more widespread, drug-resistant bacteria unable to be destroyed could one day change that.