Drug Resistant E. coli Moves to U.S.

The first reported incidence of a colistin-resistant E. coli. Has been reported in Pennsylvania.

The U.S. military science blog has reported that the Multidrug-resistant Organism Repository and Surveillance Network (MRSN) at the Walter Reed Institute of Research had identified the first colistin-resistant mcr-1 E. coli in a person in the United States. A USDA and HHS search for colistin-resistant bacteria in food animals, retail meats and people also has found colistin-resistant E. coli in a single sample from a pig intestine.

Other reports are that this occurred in a middle-aged woman in Pennsylvania and that although the particular strain was treatable with other antibiotics this is a critical final stage in the development of a true superbug which is resistant to all antibiotics.

The reason is that this particular strain of the common Gram-negative E. coli bacteria carries the mcr-1 resistance gene which is a free floating strand of DNA meaning it can easily be shared with and transferred to other strains, many of which may be resistant to every other antibiotic except for the 50-year old colistin drug which was almost completely discontinued in the 70’s due to its human toxicity.

Once that colistin resistance gene moves to another Gram-negative bacteria strain which is already resistant to everything else we will have a common infectious agent for which there is no treatment.

Last year President Obama released a National Action Plan for Combating Antibiotic Resistant Bacteria charging the military to treat drug resistant infections as a top priority and a major threat.

According to the NIH,“The problem with re-introducing an older drug, such as colistin, though, is that techniques for evaluating new drugs have evolved since the 1950s, and therefore, little is known about the dose needed to effectively fight infection while limiting the potential emergence of antimicrobial resistance and reducing potentially toxic side effects. More data are needed to guide optimal use of these older medications.”

For detailed information see American Society for Microbiology, “Escherichia coli Harboring mcr-1 and blaCTX-M on a Novel IncF Plasmid: First report of 2 mcr-1 in the USA”