KUALA LUMPUR, June 19 — For the first time, a bacterial gene that grants resistance to “last resort” antibiotics has been detected in a patient in the US. News of this discovery was recently published in the Journal of Medical Microbiology.
Though the existence of the gene has been known earlier to exist in other countries, it is particularly concerning as the test sample was from 2014, indicating that it is likely to already be widespread across the US.
There are fears that the gene could have already spread to other bacteria including E.coli.
The gene was detected during routine surveillance for new strains of drug-resistant bacteria looking at 100 clinical human stool samples collected between 2014 and 2016, taken from people in the southeastern US.
The mcr-3.1 gene was found in a sample, obtained from an individual who acquired a Salmonella infection after travelling to China.
Salmonella is a bacteria commonly associated with incidences of food poisoning. In severe cases, antibiotics often are prescribed.
However, antimicrobial resistance has begun to increase as a result of over-prescribing leading the bacteria becoming resistant to most existing antibiotics. Colistin is an antibiotic considered to be the drug of “last resort”.
The mcr-3.1 gene gives bacteria the ability to resist colistin, making any infection untreatable using any current antibiotics.
“In 2015, they saw that mcr-3.1 had moved from a chromosome to a plasmid in China, which paves the way for the gene to be transmitted between organisms. For example, E. coli and Salmonella are in the same family, so once the gene is on a plasmid, that plasmid could move between the bacteria and they could transmit this gene to each other. Once mcr-3.1 jumped to the plasmid, it spread to 30 different countries, although not – as far as we knew – to the US,” said Siddhartha Thakur, author of the study.
This news now confirms the existence of the gene on US soil.