Use antibiotics for pigs, and humans harvest drug-resistant genes?
Worldwide, animal resistance to colistin has surprised researchers
Eighteen months ago, there was a gene that developed resistance to colistin, also known as the last antibiotic, in bacteria in pigs in China.
According to New Orleans in the United States last week at the American society for microbiology (ASM) conference report, from then on, this is known as the MCR - 1 drug-resistant genes with shocking speed spread throughout the world.
In some places, nearly 100 percent of livestock carry MCR - 1, and a growing number of people have the same gene.
Lance Price, an antibiotic researcher at George Washington university in the United States, says its spread clearly shows that antibiotics can lead to resistance in humans.
Misuse of antibiotics in domestic animals may be producing drug-resistant bacteria.
Colistin appears in the 1950s, but is rarely used in humans because it can lead to kidney disease.
However, many countries use it to promote the growth of livestock -- a practice that provides conditions for the emergence of bacteria that are resistant to colistin.
That's the problem, because over the last decade, doctors have increasingly used mycorycin in patients who don't respond to other antibiotics.
"It's a bad drug, and I think it's a sign of desperation, and we're very worried about losing a toxic antibiotic," Price commented.
Increasing drug resistance
Although colistin resistance genes in bacteria natural evolution, but when researchers reported last year in China from bacterial genome to plasmid MCR - 1 (circular DNA to transfer between different species of bacteria) on, public health experts began to worry.
Some evidence suggests that plasmids that carry McR-1 have been on the farm for decades, and researchers now see these plasmids and genes because they are consciously looking for them.
But they appear to be increasing in frequency.
The researchers found the McR-1 in 497 samples from 8,000 samples of human fecal bacteria collected from guangzhou, China, over five years.
Meanwhile, microbiologist tian guobao of sun yat-sen university in guangzhou, China, noted at the ASM conference that the popularity of the McR-1 gene has become more widespread during this period.
Tian and his colleagues found that 10 percent of the McR-1 gene appears in e. coli strains, which are resistant to other antibiotics.
The researchers found the McR-1 in 497 samples from 8,000 samples of human fecal bacteria collected from guangzhou, China, over five years.
Meanwhile, microbiologist tian guobao of sun yat-sen university in guangzhou, China, noted at the ASM conference that the popularity of the McR-1 gene has become more widespread during this period.
Tian and his colleagues found that 10 percent of the McR-1 gene appears in e. coli strains, which are resistant to other antibiotics.
Although these two genes found in different plasmid, but a plasmid carrying on multiple drug resistance genes are common, the United States at the university of Iowa state veterinary microbiologist Catherine Logue said.
Even treatments that use only one drug can attack multiple bacteria with these plasmids, so it's possible to increase the gene's resistance to a variety of drugs.
Sound the alarm
In a speech at ASM conference, Logue and her team said they had found genes that were resistant to the antibiotics and antibiotics that are similar to penicillin.
Brazil is the world's largest exporter of poultry, and analysed samples from 107 farms in Brazil, with about 60 percent of the strains of e. coli that carry McR-1.
In two randomly selected Portuguese farms, McR-1 is more common: 98% of the 100 healthy pigs study samples contain resistance genes, says Laurent Poirel.
He was an antibiotic resistance researcher at the university of fribourg in Switzerland and this time at ASM congress.
He and his colleagues also in three different kinds of plasmid and a variety of bacteria strains were found in MCR - 1, which means the home pig is not necessarily in the dissemination of resistance genes between each other, it is also possible from other sources.
"We don't know how it came about," Laurent said.
It also found McR-1 in a number of different plasmids and bacterial strains.
This gene seems to be particularly good at transferring to different organisms, explains Logue, which makes it extremely survivable and makes it extremely difficult to deal with.
If people eat not cooked meat, or in the workplace exposure to carry the bacteria containing MCR - 1 animal, so in theory his gut microbes may also obtain the resistance genes.
Price is appalled at the ubiquity of McR-1 found in these countries.
In 2016, Brazil banned the use of colistin in agricultural production, and in 2017 China imposed a ban.
But Price isn't sure how much it will slow down the spread of these genes.
He hopes the McR-1 case will serve as a cautionary tale for farm animals abusing antibiotics.
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