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Source: http://www.cidrap.umn.edu/news-pers...st-e-coli-resistant-both-colistin-carbapenems
US first: E coli resistant to both colistin, carbapenems
Filed Under:
Antimicrobial Stewardship; E coli
Chris Dall | News Reporter | CIDRAP News
| Aug 30, 2016
US researchers say they've identified a strain of Escherichia coli that is resistant to both colistin and carbapenem antibiotics in a US hospital patient.
According to a study published today in the journal mBio, the strain was isolated from the urine of a 76-year-old male patient who was being treated for a urinary tract infection at a New Jersey hospital in 2014. Whole-genome sequencing of the isolate, performed this year, confirmed the presence of the MCR-1 and blaNDM-5 genes, which confer resistance to colistin and carbapenems, respectively. The strain was found to harbor resistance genes to several other antibiotics, as well.
The finding confirms fears that were aroused when researchers in China first identified the colistin-resistance gene MCR-1 in E coli isolates from pigs, pork products, and humans in November 2015. Colistin is considered an antibiotic of last resort in humans, used mainly when bacterial infections won't respond to other drugs.
To date, more than 30 countries?including the United States?have reported finding bacteria containing the gene in samples from humans, animals, and the environment.
Because MCR-1 is carried on mobile pieces of DNA called plasmids that can easily be shared with other types of bacteria, public health officials have warned of the possibility of the gene hooking up with gram-negative bacteria that are resistant to other antibiotics?like carbapenem-resistant Enterobacteriacea?and creating "superbugs" that are nearly impossible to treat.
[h=3]Good news and bad news[/h] While other countries have reported E coli strains harboring both MCR-1 and blaNDM-5, the authors of the study say this appears to be the first case to be reported in the United States. In this case, the patient's urinary tract infection did respond to other antimicrobial agents. But the authors warn that other E coli strains carrying the two resistance genes, which are carried on separate plasmids, are likely out in the community.
"The good news is that this did not cause a major outbreak of drug-resistant infection," senior study author Barry N. Kreiswirth, PhD, director of Rutgers University's Public Health Research Institute, said in a news release from the American Society for Microbiology (ASM), which publishes mBio. "The bad news is that since this occurred two years ago, there are clearly other strains out there we haven't detected yet."
Study co-author Jose R. Mediavilla, MBS, MPH, said the E coli strain identified in the patient was a variant of ST405, which has been frequently identified with community-onset urinary tract infections.
Kreiswirth and Mediavilla said the finding indicates the need for active surveillance for bacteria that carry both genes, in order to prevent further dissemination.
MCR-1-harboring E coli has been previously reported in the United States. In May, investigators with the Walter Reed Army Institute of Research reported finding the gene in a strain obtained from a Pennsylvania woman this year. In a study published in July, researchers identified the gene in an E coli isolate obtained from a New York hospital in 2015.
See also:
Aug 30 mBio study
Aug 30 ASM news release
May 26 CIDRAP News story "Highly resistant MCR-1 'superbug' found in US for first time"
Jul 11 CIDRAP News story "MCR-1 gene found in human sample in US for 2nd time"
US first: E coli resistant to both colistin, carbapenems
Filed Under:
Antimicrobial Stewardship; E coli
Chris Dall | News Reporter | CIDRAP News
| Aug 30, 2016
US researchers say they've identified a strain of Escherichia coli that is resistant to both colistin and carbapenem antibiotics in a US hospital patient.
According to a study published today in the journal mBio, the strain was isolated from the urine of a 76-year-old male patient who was being treated for a urinary tract infection at a New Jersey hospital in 2014. Whole-genome sequencing of the isolate, performed this year, confirmed the presence of the MCR-1 and blaNDM-5 genes, which confer resistance to colistin and carbapenems, respectively. The strain was found to harbor resistance genes to several other antibiotics, as well.
The finding confirms fears that were aroused when researchers in China first identified the colistin-resistance gene MCR-1 in E coli isolates from pigs, pork products, and humans in November 2015. Colistin is considered an antibiotic of last resort in humans, used mainly when bacterial infections won't respond to other drugs.
To date, more than 30 countries?including the United States?have reported finding bacteria containing the gene in samples from humans, animals, and the environment.
Because MCR-1 is carried on mobile pieces of DNA called plasmids that can easily be shared with other types of bacteria, public health officials have warned of the possibility of the gene hooking up with gram-negative bacteria that are resistant to other antibiotics?like carbapenem-resistant Enterobacteriacea?and creating "superbugs" that are nearly impossible to treat.
[h=3]Good news and bad news[/h] While other countries have reported E coli strains harboring both MCR-1 and blaNDM-5, the authors of the study say this appears to be the first case to be reported in the United States. In this case, the patient's urinary tract infection did respond to other antimicrobial agents. But the authors warn that other E coli strains carrying the two resistance genes, which are carried on separate plasmids, are likely out in the community.
"The good news is that this did not cause a major outbreak of drug-resistant infection," senior study author Barry N. Kreiswirth, PhD, director of Rutgers University's Public Health Research Institute, said in a news release from the American Society for Microbiology (ASM), which publishes mBio. "The bad news is that since this occurred two years ago, there are clearly other strains out there we haven't detected yet."
Study co-author Jose R. Mediavilla, MBS, MPH, said the E coli strain identified in the patient was a variant of ST405, which has been frequently identified with community-onset urinary tract infections.
Kreiswirth and Mediavilla said the finding indicates the need for active surveillance for bacteria that carry both genes, in order to prevent further dissemination.
MCR-1-harboring E coli has been previously reported in the United States. In May, investigators with the Walter Reed Army Institute of Research reported finding the gene in a strain obtained from a Pennsylvania woman this year. In a study published in July, researchers identified the gene in an E coli isolate obtained from a New York hospital in 2015.
See also:
Aug 30 mBio study
Aug 30 ASM news release
May 26 CIDRAP News story "Highly resistant MCR-1 'superbug' found in US for first time"
Jul 11 CIDRAP News story "MCR-1 gene found in human sample in US for 2nd time"