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06-01-2016, 02:10 AM
An honorable member of the Coffee Shop Has Just Posted the Following:
An alarming new superbug gene that makes bacteria resistant to a last-resort antibiotic has been detected in Canada, the Star has learned.
The gene, called MCR-1, produces an enzyme that makes bacteria invincible to colistin, a highly toxic antibiotic used only when all other drugs have failed.
MCR-1 was first reported in November by scientists in China, who published a paper in The Lancet that set off alarm bells across the globe. Analyzing bacterial samples in southeastern China, researchers found 260 samples of E. coli with the MCR-1 gene on meat, hospital patients and farm animals — the likely source of this new superbug, the paper suggests.
But the news that really sent a shudder through the scientific community was that MCR-1 is located on a plasmid, a free-floating snippet of DNA that bacteria can easily share, thus spreading the resistance to other organisms.
“It’s clearly the biggest story to come out (in 2015),” said Lance Price, a professor of environmental health at George Washington University who studies antibiotic resistance. “There have been horrible things all year but this is the most disturbing.”
So far, there have been no reports of deaths caused by MCR-1 and some people could be harbouring the superbug asymptomatically. But the nightmare scenario is that MCR-1 will spread to more virulent bacterial strains that also carry other resistance genes — thus creating a “pan-resistant” superbug capable of defeating every antibiotic in the medicine cabinet.
Since the Lancet paper, at least a dozen other countries have also found the MCR-1 gene. Scientists, looking through databases of bacterial samples, detected the gene everywhere from Denmark and Algeria to Laos.
Among them is Canada, where an investigation was triggered in December by the Public Health Agency of Canada. The Canadian findings have not yet been published, but a case report has been submitted to the Lancet, according to Dr. Michael Mulvey, chief of antimicrobial resistance with the PHAC’s lab in Winnipeg.
The superbug gene was found in three different samples of E. coli, all previously collected for special research projects: one from a 62-year-old patient in Ottawa and two from ground beef sold in Ontario.
The Ottawa patient likely picked up the bug in Egypt, where she lived for several years, according to Dr. Baldwin Toye with the Ottawa hospital, who co-wrote a 2013 paper describing her case and four others.
She was hospitalized three days after moving back to Canada and treated for an abdominal infection. Toye believes another pathogen was responsible for her illness, however, and the patient was simply harbouring the MCR-1 gene, which Mulvey discovered retrospectively during his recent investigation.
Meanwhile, the ground beef samples were found nearly a year apart in different locations in Ontario, a butcher shop and a grocery chain, according to Mulvey. Both were collected in 2010, predating the samples from China, which were collected between 2011 and 2014.
“To see it show up was a surprise for me,” Mulvey said. “It supports that there’s global dissemination of this gene already … we’re now going to have to look back even prior to (2010), because maybe it’s been around for even longer.”
For scientists worried about antibiotic resistance, the emergence of colistin resistance is troubling but comes as no surprise. Bacteria are naturally equipped with resistance mechanisms, but the overuse — and misuse — of antibiotics has exerted an unnatural pressure on bacteria to evolve. Those that can withstand antibiotics survive and reproduce.
Colistin, which belongs to a group of antibiotics called the polymyxins, was actually discovered in the late 1940s but was quickly shelved due to its highly toxic side effects. Pharmaceutical companies moved on to develop other, better antibiotics — but, one by one, bacteria have evolved strategies for knocking them down.
“We’ve sort of run out of our good drugs,” Price said. “So out of desperation … we have to revive this old drug because it’s all we have left.”
Colistin is still rarely used in human medicine because doctors want to conserve the antibiotic’s effectiveness. But polymyxins are often given to livestock animals to prevent infections and promote growth — especially in China, one of the world’s highest users of colistin in agriculture. (While colistin isn’t used in agriculture in Canada, polymyxin B — a similar compound that creates the same resistance problems as colistin — is.)
In 2015, the global market for colistin in agriculture reached nearly 12,000 tonnes and is expected to rise to 16,500 tonnes by 2021, according to the Lancet paper. “That’s insane,” said Dr. Gerry Wright, a microbiologist with McMaster University and expert in antibiotic resistance.
Scientists have already seen colistin resistance emerge. In Canada, for example, ongoing hospital surveillance stemming back to 2010 has found 13 samples of colistin-resistant bacteria, according to Mulvey.
But MCR-1 is unique in that it’s located on a plasmid which bacteria can share even with different species — the equivalent of a human sharing its DNA with a tree.
“For many years, scientists, including me, have been living under the misapprehension that you could never ever get mobile colistin resistance,” said Timothy Walsh, a microbiologist with Cardiff University who co-authored the initial Lancet paper. “And once it’s mobilized, what tends to happen is it transfers much more quickly.”
Walsh said the Chinese government is taking MCR-1 seriously and he expects it will announce an official ban on colistin use in agriculture.
But microbiologists like Wright, who is now studying MCR-1, would like to see polymyxins banned from agricultural use in every country, including Canada.
“Any antibiotic class used for humans should never be used for animals (unless they’re sick),” he said. “I just find it absolutely mind-boggling that we’re going into 2016 and we’re still having this discussion.”
Click here to view the whole thread at www.sammyboy.com (http://singsupplies.com/showthread.php?222948-Ah-Tiong-creates-and-export-superbugs&goto=newpost).
An alarming new superbug gene that makes bacteria resistant to a last-resort antibiotic has been detected in Canada, the Star has learned.
The gene, called MCR-1, produces an enzyme that makes bacteria invincible to colistin, a highly toxic antibiotic used only when all other drugs have failed.
MCR-1 was first reported in November by scientists in China, who published a paper in The Lancet that set off alarm bells across the globe. Analyzing bacterial samples in southeastern China, researchers found 260 samples of E. coli with the MCR-1 gene on meat, hospital patients and farm animals — the likely source of this new superbug, the paper suggests.
But the news that really sent a shudder through the scientific community was that MCR-1 is located on a plasmid, a free-floating snippet of DNA that bacteria can easily share, thus spreading the resistance to other organisms.
“It’s clearly the biggest story to come out (in 2015),” said Lance Price, a professor of environmental health at George Washington University who studies antibiotic resistance. “There have been horrible things all year but this is the most disturbing.”
So far, there have been no reports of deaths caused by MCR-1 and some people could be harbouring the superbug asymptomatically. But the nightmare scenario is that MCR-1 will spread to more virulent bacterial strains that also carry other resistance genes — thus creating a “pan-resistant” superbug capable of defeating every antibiotic in the medicine cabinet.
Since the Lancet paper, at least a dozen other countries have also found the MCR-1 gene. Scientists, looking through databases of bacterial samples, detected the gene everywhere from Denmark and Algeria to Laos.
Among them is Canada, where an investigation was triggered in December by the Public Health Agency of Canada. The Canadian findings have not yet been published, but a case report has been submitted to the Lancet, according to Dr. Michael Mulvey, chief of antimicrobial resistance with the PHAC’s lab in Winnipeg.
The superbug gene was found in three different samples of E. coli, all previously collected for special research projects: one from a 62-year-old patient in Ottawa and two from ground beef sold in Ontario.
The Ottawa patient likely picked up the bug in Egypt, where she lived for several years, according to Dr. Baldwin Toye with the Ottawa hospital, who co-wrote a 2013 paper describing her case and four others.
She was hospitalized three days after moving back to Canada and treated for an abdominal infection. Toye believes another pathogen was responsible for her illness, however, and the patient was simply harbouring the MCR-1 gene, which Mulvey discovered retrospectively during his recent investigation.
Meanwhile, the ground beef samples were found nearly a year apart in different locations in Ontario, a butcher shop and a grocery chain, according to Mulvey. Both were collected in 2010, predating the samples from China, which were collected between 2011 and 2014.
“To see it show up was a surprise for me,” Mulvey said. “It supports that there’s global dissemination of this gene already … we’re now going to have to look back even prior to (2010), because maybe it’s been around for even longer.”
For scientists worried about antibiotic resistance, the emergence of colistin resistance is troubling but comes as no surprise. Bacteria are naturally equipped with resistance mechanisms, but the overuse — and misuse — of antibiotics has exerted an unnatural pressure on bacteria to evolve. Those that can withstand antibiotics survive and reproduce.
Colistin, which belongs to a group of antibiotics called the polymyxins, was actually discovered in the late 1940s but was quickly shelved due to its highly toxic side effects. Pharmaceutical companies moved on to develop other, better antibiotics — but, one by one, bacteria have evolved strategies for knocking them down.
“We’ve sort of run out of our good drugs,” Price said. “So out of desperation … we have to revive this old drug because it’s all we have left.”
Colistin is still rarely used in human medicine because doctors want to conserve the antibiotic’s effectiveness. But polymyxins are often given to livestock animals to prevent infections and promote growth — especially in China, one of the world’s highest users of colistin in agriculture. (While colistin isn’t used in agriculture in Canada, polymyxin B — a similar compound that creates the same resistance problems as colistin — is.)
In 2015, the global market for colistin in agriculture reached nearly 12,000 tonnes and is expected to rise to 16,500 tonnes by 2021, according to the Lancet paper. “That’s insane,” said Dr. Gerry Wright, a microbiologist with McMaster University and expert in antibiotic resistance.
Scientists have already seen colistin resistance emerge. In Canada, for example, ongoing hospital surveillance stemming back to 2010 has found 13 samples of colistin-resistant bacteria, according to Mulvey.
But MCR-1 is unique in that it’s located on a plasmid which bacteria can share even with different species — the equivalent of a human sharing its DNA with a tree.
“For many years, scientists, including me, have been living under the misapprehension that you could never ever get mobile colistin resistance,” said Timothy Walsh, a microbiologist with Cardiff University who co-authored the initial Lancet paper. “And once it’s mobilized, what tends to happen is it transfers much more quickly.”
Walsh said the Chinese government is taking MCR-1 seriously and he expects it will announce an official ban on colistin use in agriculture.
But microbiologists like Wright, who is now studying MCR-1, would like to see polymyxins banned from agricultural use in every country, including Canada.
“Any antibiotic class used for humans should never be used for animals (unless they’re sick),” he said. “I just find it absolutely mind-boggling that we’re going into 2016 and we’re still having this discussion.”
Click here to view the whole thread at www.sammyboy.com (http://singsupplies.com/showthread.php?222948-Ah-Tiong-creates-and-export-superbugs&goto=newpost).