Newly Identified Strain of E. Coli Bacteria Resistant to the “Antibiotic of Last Resort”

Antibiotics and similar drugs, together called antimicrobial agents, have been used for the last 70 years to treat patients who have infectious diseases. Since the 1940s, these drugs have greatly reduced illness and death from infectious diseases. However, these drugs have been used so widely and for so long that the infectious organisms the antibiotics are designed to kill have adapted to them, making the drugs less effective. According to the Centers for Disease Control (CDC) at least 2 million people become infected with bacteria that are resistant to antibiotics and at least 23,000 people die each year as a direct result of these infections.

Photo Credit: Janice Haney Carr, Centers for Disease Control and Prevention

Lena H. Sun’s writing in The Washington Post (Superbug investigation: ‘It’s likely that more of these will be found,’ CDC says) noted that researchers at Walter Reed Army Institute of Research in Silver Spring, MD have recently identified a new strain of E. coli bacteria that contains a gene which makes it resistant to the “antibiotic of last resort.” The new strain of superbug was found in a Pennsylvania woman in April 2016

Sun reported that it’s likely that more people will be found to be carrying a newly discovered superbug. Sun quotes Beth Bell, an expert on antibiotic resistance at the Centers for Disease Control and Prevention. Bell also said officials investigating the Pennsylvania superbug case don’t know how the strain of E. coli wound up in the woman’s body. And they may never find out, she said. This particular E. coli bacterium contained a gene, known as mcr-1, that makes it resistant to the antibiotic colistin. This drug (drug of last resort) is used against particularly dangerous types of superbugs that can already withstand other antibiotics. This discovery has public health officials worried because it’s the first time this colistin-resistant gene has been found in samples studied from here in the United States. Over the long term, experts are worried that colistin resistance, which can spread easily to other bacteria through this gene, could lead to superbugs that could cause untreatable infections.

Sun reports that while this discovery should not be allowed to foster undue worry or alarm, she also notes that researchers at the Agriculture Department and the Department of Health and Human Services reported that testing of hundreds of livestock and retail meats turned up the same colistin-resistant bacteria in a sample from a pig intestine in the United States. It is not a “panic button” situation but it is a serious and alarming finding and further complicates the looming public health crisis of antimicrobial resistance.

Antimicrobial Resistance (AMR)

Antimicrobial resistance (AMR) occurs when a microbe adapts to increase resistance or becomes fully resistant to antimicrobials which previously could treat it. Such resistance arises through one of three ways: (1) natural resistance in certain types of bacteria; (2) genetic mutation; or (3) by one species acquiring resistance from another. Such evolutionary mutations may be promoted by the widespread use of antibiotics: in the human population; in the animal population; as well as the spread of resistant strains between human or non-human sources.

Resistant microbes are already increasingly difficult to treat, requiring alternative medications or higher doses of drugs —which in turn may be costlier or potentially more toxic. Microbes resistant to multiple antimicrobials are called multidrug resistant (MDR). Antimicrobial resistance is on the rise with millions of deaths every year. A few infections are now completely untreatable due to resistance. All classes of microbes develop resistance (fungi, antifungal resistance; viruses, antiviral resistance; protozoa, antiprotozoal resistance; bacteria, antibiotic resistance).

This animated video from 2013 from the Centers for Disease Control and Prevention highlights the key points and graphics of the “Antibiotic Threats in the United States” report. This animated video from 2013 from the Centers for Disease Control and Prevention highlights the key points and graphics of the “Antibiotic Threats in the United States” report. (YouTube/CDC)

AMR: A Global Health Risk

A World Health Organization (WHO) report released April 2014 stated, “this [antimicrobial resistance] serious threat is no longer a prediction for the future, it is happening right now in every region of the world and has the potential to affect anyone, of any age, in any country. Antibiotic resistance—when bacteria change so antibiotics no longer work in people who need them to treat infections—is now a major threat to public health.”

One study conducted by the Centers for Disease Control has found that every year, 2 million Americans fall ill and nearly 23,000 people die due to antibiotic-resistant bacteria. Dr. Brad Spellberg with the Infectious Diseases Society of America weighs in on the severity of the situation in the following video:

Mitigation Steps and Health Education Essential

There is an urgent need for health communication about AMR and steps that both health care providers and individuals (patients) can take to help mitigate these risks. We have to increase awareness, educate and change behaviors at all levels of the health care cycle.

Antibiotics should only be prescribed/used when needed and only as specifically prescribed by health professionals. Health care providers should closely adhere to the five RIGHTS of drug administration: the right patient, the right drug, the right dose, the right route and the right time.

Narrow-spectrum antibiotics should be preferred over broad-spectrum antibiotics when possible, as effectively and accurately targeting specific organisms is less likely to cause resistance. Bacteria cultures should be taken before treatment when indicated and treatment potentially changed based on the susceptibility report. For people who take these medications at home, education about proper use is essential. Health care providers can minimize spread of resistant infections by use of proper sanitation: including hand washing and disinfecting between patients; and should encourage the same of the patient, visitors and family members.

For more information, please view the following CDC video:

Related content written by Dr. Robert C. Chandler:

Emergency Department Drug Shortages – The Next Healthcare Crisis

Effective Health Communication: Drug Resistant Infectious Super Bugs

Health Risk Communication: Foodborne Illness and Food Product Safety