Bacteria Resistant

Bacteria resistant to ‘last resort’ antibiotic found in Los Angeles for first time  

Posted by

2


The discovery was made while surveilling the untreated waters of Los Angeles’ largest treatment plants—the Joint Water Pollution Control Plant in Carson and the Hyperion Water Reclamation Plant in Playa del Rey— a practice that began following Covid pandemic. 

STORY HIGHLIGHTS

It has alarmed scientists as this antibiotic—for which evidence of resistance has been found—is used when all other drugs, especially penicillin, fail to respond

Researchers in Los Angeles have for the first time found bacteria that is highly resistant to colistin, considered to be the “last resort” antibiotic, in the US county’s wastewaters. 

The discovery was made while surveilling the untreated waters of Los Angeles’ largest treatment plants—the Joint Water Pollution Control Plant in Carson and the Hyperion Water Reclamation Plant in Playa del Rey— a practice that began following Covid pandemic. 

Both facilities serve a total of about 7.5 million people, the Los Angeles Times newspaper reported. 

It has alarmed scientists as this antibiotic—for which evidence of resistance has been found—is used when all other drugs, especially penicillin, fail to respond.  

“Testing found antibiotic resistance genes on two novel small plasmids, circular pieces of DNA that can be shared among different types of unrelated bacteria,” said researcher Adam Smith, associate professor of environmental engineering at USC, whose findings were published in Environmental Science & Technology Letters. 

“This is probably the scariest aspect: the potential for this resistance to spread widely across different bacterial populations,” Smith said. 

He noted that this type of antibiotic resistant gene has been found in “six of seven continents”, but this is the first time that traces of this antibiotic resistance have been found in LA. 

According to the World Health Organisation (WHO), antibiotic resistance is one of the major threats to global health, food security, and development. 

Although it occurs naturally, misuse of antibiotics in humans and animals is believed to be triggering the process. 

The global health agency noted that it is becoming difficult to treat a growing number of infections, such as pneumonia, tuberculosis, gonorrhea, and salmonellosis, as antibotics are becoming less effective. 

“We could get to the point where we can’t combat infections with antibiotics,” Smith said, “so we’re entering sort of a post-antibiotic world.” 

What’s particularly concerning is that antibiotic resistance leads to longer hospital stays, higher medical costs and increased mortality. 

Colistin was originally discovered in 2015 in China and has been documented on every continent except Antarctica, Smith said.  

That includes in Los Angeles, where a resident who died in 2016 was found to have been infected with E. coli bacteria that carried a colistin resistance gene.

New Study Raises Specter of More Bacteria Resistant to Last Line Antibiotics

Posted by

0


Study examined bacteria resistant to carbapenems, a class of antibiotics considered last-resort.

 

This illustration depicts a three-dimensional (3D) computer-generated image of a group of carbapenem-resistant Enterobacteriaceae (CRE) bacteria. Untreatable and hard-to-treat infections from carbapenem-resistant Enterobacteriaceae (CRE) bacteria are on the rise among patients in medical facilities.

This illustration depicts a three-dimensional (3D) computer-generated image of a group of carbapenem-resistant Enterobacteriaceae (CRE) bacteria. Untreatable and hard-to-treat infections from carbapenem-resistant Enterobacteriaceae (CRE) bacteria are on the rise among patients in medical facilities.

Bacteria resistant to last line antibiotics are likely circulating more widely than currently reported and among people with no signs of infection, according to a new genetic analysis of resistant bacteria found in patients at four U.S. hospitals.

The findings highlight the need for more surveillance of even apparently healthy people to trace the sources of infections in hospitals, said the researchers and several infectious-disease experts.

“It’s hard to get a problem under control when you don’t know the extent, and this is suggesting we don’t know the extent,” says Massachusetts General Hospital infectious-disease physician Deborah Hung. Dr. Hung, co-director of the Infectious Disease and Microbiome Program at the Broad Institute and other scientists from the Institute were part of the research team.

As sequencing DNA has gotten cheaper and faster, researchers are now able to sequence the whole genomes of several hundred bacteria for a fraction of the previous cost. Analyzing the DNA of antibiotic-resistant bacteria has helped scientists learn how the organisms become immune to drugs and trace transmission via bacteria that share much of their genetic material.

For the new research, published Monday in the Proceedings of the National Academy of Sciences, scientists sequenced and compared the genomes of bacteria collected from patients whose infections were resistant to carbapenems, a class of antibiotics considered last-resort.

“We found very few cases of disease” in which the bacteria were closely related to each other says Bill Hanage, an epidemiologist at the Harvard T. H. Chan School of Public Health’s Center for Communicable Disease Dynamics and senior author on the paper. If patients had been infected by each other or from the same source, the bacteria from their samples would have shared more DNA in common. The lack of similarity suggests that the bacteria, collected in 2012 and 2013 from infected patients of Massachusetts General Hospital, Beth Israel Deaconess Medical Center, Brigham and Women’s Hospital and by University of California, Irvine School of Medicine researchers, weren’t passed directly from one patient to another, but rather through a network of asymptomatic carriers.

“It’s entirely plausible that these bacteria could be transmitted unseen among people,” Dr. Hanage says, via common bacterial residents of the human gut Escherichia coli and Klebsiella pneumoniae, which typically cause no harm unless they spread to another part of the body of a susceptible person. “We are not going to know exactly how much that’s happening until we go and look for it.”

Asymptomatic carriers of carbapenem-resistant bacteria could be a major driver of hospital infections and the finding “provides further evidence of the need for active surveillance strategies,” says Joshua Thaden, a physician in the Duke University School of Medicine Division of Infectious Disease, who wasn’t involved in the research.

Currently, the Centers for Disease Control and Prevention collects reports of carbapenem-resistant infections, but hospitals are not required to report them, and few if any U.S. hospitals screen asymptomatic people for antibiotic-resistant bacteria.

The scientists also found new mechanisms of carbapenem resistance in the bacteria they sampled. “This suggests that the barrier to becoming resistant is potentially much lower than we thought,” Dr. Hung says, which could prove a problem for developing tests that quickly identify bacteria carrying genes known to cause resistance.

Bacteria Resistant to Last-Resort Antibiotic Discovered in U.S.

Posted by

0


Escherichia coli resistant to colistin — the last-resort antibiotic used to treat carbapenem-resistant bacteria — has been identified in the U.S. for the first time, researchers report in Antimicrobial Agents and Chemotherapy. If colistin resistance eventually extends to carbapenem-resistant bacteria, those microbes will become “unstoppable,” the New York Times notes.

The resistant E. coli was found in a woman who presented to a Pennsylvania military clinic in late April with a urinary tract infection. Her urine sample was sent to a research institute that, in May, began testing certain E. coli isolates for colistin resistance. The woman’s E. coli strain carried 15 antibiotic resistance genes, including the colistin resistance gene, mcr-1. It was not resistant to carbapenems, however.

This E. coli strain has previously been identified in Europe and Asia, although the patient — who has recovered — reported no recent travel.

Infectious disease expert Dr. Paul Sax commented: “Although only a single case, this report underscores that highly resistant bacteria are now found both in and out of the hospital — and raises the importance of policies and programs that limit antibiotic use.”

Why We Chose This as Our Top Story:

André Sofair, MD, MPH: I completely agree with what Dr. Paul Sax has already stated. Even though this is one single documented case, this report highlights the importance of appropriate antibiotic stewardship at both the hospital and practitioner levels.

Bacteria Resistant to ALL Drugs Shows up in Denmark

Posted by

0


Is this the start of an epidemic of untreatable infections?

Bacteria resistant to ALL antibiotics have arrived in Europe, and experts fear it could be the start of a global epidemic of untreatable infections.

Bacteria Resistant to ALL Drugs Shows up in Denmark
Last month, we reported on a gene mutation called MCR-1 that had shown up in bacteria in China. The mutation is resistant to all antibiotics, including colistin, a last-resort drug used to tackle tough bacteria when all other antibiotics have failed.
The superbugs were found in 15% of raw meat samples in China, as well as a fifth of the animals tested. Colistin had also failed in 16 patients infected with drug-resistant infections.
Now a patient in Denmark has been diagnosed with an untreatable form of salmonella, scientists from George Washington University (GWU) and the Statens Serum Institute (SSI) and National Food Institute (NFI) in Denmark announced Friday. In addition, they also found untreatable bacteria in 5 samples of chicken imported from China through Germany.

The Antibiotic Resistance Action Center in the Milken Institute School of Public Health at GWU, said in a statement to National Geographic:
“The news that the dangerous colistin resistance gene has been found in Denmark is alarming. This newly identified gene, called MCR-1, is on a mobile piece of DNA that can make copies of itself and then jump to from bacterium to bacterium, spreading resistance. History shows that these mobile resistance genes can spread around the world quickly, silently riding in people, animals, and food. The news that MCR-1 has been discovered in Denmark suggests that this scenario is playing out in real time.”
The Danish researchers said that when they learned of the new resistance factor, they immediately took a look at the stored genomes they held at their institutions to look for it:
“The approximately 3,000 Gram-negative (E. coli or Salmonella) bacteria, which have previously been mapped using whole genome sequencing, have been reexamined to see whether MCR-1 is present. Results show that MCR-1 was found in one patient, who suffered from a blood infection in 2015 and in five food samples that have been imported from 2012-2014. All the bacteria are multi-resistant ESBL bacteria containing the MCR-1 gene, which can further complicate treatment.”
The Chinese researchers who discovered the untreatable pathogens warned that it could spread globally, but experts are shocked at how quickly they’re making their way around the globe, saying the situation is extremely serious.
And bacteria affected by the MCR-1 gene are especially frightening because they can be transferred to other types of bacteria, which means they could spread quickly between animals and humans.
Professor Frank Møller Aarestrup, a microbiologist at the Technical University of Denmark, said today: “This is a very alarming discovery.
“It is something I had feared, but hoped I would not see.”
Aarestrup said he wouldn’t be surprised if the powerful bugs had already migrated to the U.K. Scientists in New Zealand said the same.
“History shows that these mobile resistance genes can spread around the world quickly, silently riding in people, animals, and food,” said Dr. Lance Prince of GWU. “The news that MCR-1 has been discovered in Denmark suggests that this scenario is playing out in real time.”
Colistin is widely used in farming, particularly in China, where farmers feed it to pigs and chickens en masse to fatten them up. In the U.S., approximately 70% of antibiotics considered vitally important to human health are used in farm animals.
Drug resistance hasn’t become enough of a problem in the U.S. to start using colistin, but it’s only a matter of time until it’s needed. And then, surely, it will only be a matter of time until colistin stops working for Americans.
The GWU ended its statement by saying this:
“We must act swiftly to contain the spread of colistin-resistant bacteria, or we will face increasing numbers of untreatable infections. Leaders from every nation should immediately implement a ban on the use of colistin in animal agriculture. While China appears to be the biggest user of the drug, it is approved for use in the European Union and many other countries. It also is approved for use in food animals in the U.S., but drug companies holding those approvals are not actively marketing the drugs. Drug companies with these approvals should immediately withdraw these label claims to ensure that colistin is never used in U.S. animal agriculture, otherwise our livestock production facilities could become breeding grounds for untreatable superbugs.
In addition, we need to remember why colistin is the last drug available for treating these dangerous infections. We turned to it because the preferred drug class – carbapenems – became powerless against some superbugs due to overuse. Carbapenems are still effective against many bacteria, but for how long? While carbapenems are not approved for use in animal agriculture in many parts of the world, their use is not explicitly banned. World leaders should call for an immediate ban on carbapenems to protect them for future generations.”

Scientists Have Found Bacteria Resistant To ‘Last Resort’ Drug

Posted by

0


Scientists have discovered a bacteria mutation that they say is resistant to an antibiotic typically considered “the last line of defense” against virulent strains of E. coli and pneumonia.

In a report published Thursday in The Lancet Infectious Diseases, a U.K.-based medical journal, the scientists wrote that they’d found colistin-resistant bacteria on a Chinese pig farm. Later, they observed the resistant bacteria in raw meat and even humans.

Colistin, a 50-year-old drug used on animals more than humans, is given to people only when all other antibiotics have proven ineffective.

The resistant mutation, dubbed the MCR-1 gene, was found in one-fifth of the 804 animals observed. It also showed up in 15 percent of the 523 raw meat samples and in 1 percent of the 1,332 patients observed in the roughly three-year study.

“The links between agricultural use of colistin, colistin resistance in slaughtered animals, colistin resistance in food, and colistin resistance in human beings are now complete,” the researchers wrote.

Based on these findings, the researchers urged countries to reassess their use — and overuse — of antibiotics. Wired also published a cheeky-but-grim obituary for the drug.

“One of the few solutions to uncoupling these connections is limitation or cessation of colistin use in agriculture,” two of the authors wrote in published comments attached to the study. “Failure to do so will create a public health problem of major dimensions.”

Colistin can be toxic to the kidneys, which is why it fell out of favor for broad human use in the 1970s. But it’s still commonly given to livestock around the world to treat or prevent diseases. China, now the world’s largest poultry and pork producer, is a heavy user of colistin in livestock. Researchers note that in 2010 the antibiotic was the “fifth most sold group of antimicrobials” in Europe.

“If MRC-1 becomes global, which is a case of when not if, and the gene aligns itself with other antibiotic resistance genes, which is inevitable, then we will have very likely reached the start of the post-antibiotic era,” University of Cardiff professor Timothy Walsh, one of the study’s researchers, told the BBC on Thursday.

The research team comprised scientists from China, Australia and the U.K., and the study was funded by China’s Ministry of Science and Technology and the National Natural Science Foundation of China.

The scientists noted in their report that while MCR-1 is “currently confined to China,” it’s likely to spread further if the overuse of antibiotics is not stopped.

“We must all reiterate these appeals and take them to the highest levels of government or face increasing numbers of patients for whom we will need to say, ‘Sorry, there is nothing I can do to cure your infection.'”