Top public health officials worry that a freakish superbug created on Chinese pig farms may take the world by storm, and there's not much we can do about it. Scientists now are reporting the emergence of a new method of antibiotic resistance to colistin, one of the last remaining drugs that can still treat most bacterial infections.
In this week's Lancet, Chinese scientists report the first recorded resistance to colistin in common gut bacteria found in both humans and pigs.
"If it did spread, and we only had the current drugs we have now, it would be a very bad thing," said Jean Patel, director of Centers for Disease Control's office of antimicrobial resistance. "These type of bacteria would be very hard to treat."
Hard to Kill: Superbugs in Circulation
Patel and other medical experts take the threat seriously because it has the ability to easily transfer the resistance gene, MCR-1, to other bacteria. The Chinese researchers say the resistant bacteria has been found throughout China, and may have already spread to Malaysia.
In the United States, only a few highly-specialized laboratories have the ability to test for this resistant bacteria, Patel said. The CDC has asked Congress to approve a $264 million package of anti-microbial resistant initiatives including setting up a detection network across the country.
Patel said these types of E.coli bacteria normally live in the human gastrointestinal tract. Healthy people could carry them without getting sick until they spread in hospitals.
Going Viral: Pandemics in Fiction and Fact
"We see transmission in health care institutions," Patel said. "Someone who might carry it, they usually acquired it in a health are setting. Once treated with antibiotics. They can flourish and take over."
The resistant bacteria was likely the result of an overuse of colistin in Chinese pig farms, which use the drug to promote growth, according to the authors of the Lancet paper.
China is one of the world's biggest users of colistin for both livestock and aquaculture, the authors wrote.
"This increasingly heavy use of colistin could have resulted in high selective pressure in the veterinary environment and led to the acquisition of MCR-1 by E coli," according to the paper. "We anticipate that the amount of colistin used in animal feed is likely to provide survival advantage for MCR-1-producer bacterial populations over colistin-sensitive bacterial populations."
How Far Are We From a Super-Pandemic?
Mark Woolhouse, professor of infections disease epidemiology at the University of Edinburgh, says the number of weapons left to fight anti-microbial resistance is growing smaller. A new kind of antibiotic, called Teixobactin, was isolated and cultured by researchers in January, but is still several years away from commercial availability.
So too are new gene-editing techniques such as CRISPR Cas-9, which work by carefully snipping out specific genes from a cell or microorganism and leaving it to function normally, or something called phage therapy, which uses a virus to inject its genome into the bacteria and destroy it.
"They are all at the early stages. If we have a new form of resistance which will spread globally in a few years, I'm not optimistic that these will work. Still, we should keep trying."
12 Diseases That Just Won't Quit
Woolhouse believes that developing vaccines for common bacterial infections may be a better route, because they would allow the body's own natural defenses to keep the person healthy.
In the meantime, the CDC's Patel says that her agency is ramping up detection efforts for the new Chinese superbug.
"We are going to look for this mechanism of resistance in our surveillance systems to make sure we don't miss this," Patel said. "And make sure appropriate prevention strategies are in place."