Super bacteria discovery adds to antibiotic resistance concerns

July 07, 2016

Antibiotic resistance and super bacteria, have been causing major concerns as of late within the health and science communities. In fact, earlier this week a strain of drug-resistant super bacteria was discovered growing in the water off the coast of Rio de Janeiro, Brazil.

According to researchers, this bacteria, known as carbapenem-resistant Enterobacteriaceae, or CRE, entered the city's waterways when sewage coming from local hospitals got channeled into the bay. Currently, only about 51% of the city’s sewage is treated, which is on the rise compared to seven years ago when only 11% was treated.

"We have been looking for super bacteria in coastal waters during a one-year period in five beaches," researcher Renata Picao said in an article. "We found that the threats occur in coastal waters in a variety of concentrations and that they are strongly associated with pollution."

The article explains that CRE is resistant to a group of antibiotics called carbapenems. When an infection doesn’t respond to carbapenem, doctors normally use colistin, a drug that is usually reserved for infections that don’t respond to the strongest antibiotics known and is used as a last resort.

In another recent case, a woman in Pennsylvania became infected with a form of E. coli resistant to colistin. Scientists from the Multidrug Resistant Organism Repository and Surveillance Network (MSRN) at the Walter Reed Institute of Research (WRAIR) found that a gene called mcr-1 was responsible for the bacteria’s resistance to the antibiotic.

Mcr-1 is found on a plasmid, which is a portable piece of DNA that can replicate on its own, the article explains. The presence of mcr-1 means that the bacteria can develop a resistance to colistin, weakening its effectiveness as a treatment.

Now, many doctors are concerned that the mcr-1 gene could transfer to CRE bacteria, like the kind found off the shore in Brazil. Since CRE doesn’t respond to carbapenem and mcr-1 doesn’t respond to colistin, the new form of bacteria would be completely resistant to all forms of antibiotics.

Although unlikely to infect healthy people, the threat of superbugs and antibiotic resistant bacteria is still very real. Infections are more frequent in a hospital setting and in people recovering from surgery or with weakened immune systems. Falling short of creating brand-new medicines to treat bacterial infections, doctors have very few other options and therefore urge patients to take antibiotics only when absolutely necessary.

“Oftentimes people with an infection will feel better without antibiotics, and antibiotics, in a lot of cases, won’t speed up the process of getting better,” John Ross, MD, an assistant professor of medicine at Harvard Medical School said. “We need to have a conversation about how we can limit antibiotic use as a society as a whole.”

The article states multiple factors that scientists say are speeding up the process of antibiotic resistance. These include:

  • Antibiotics in agriculture. According to the CDC, using antibiotics in food-producing animals has contributed to the rise of antibiotic resistant bacteria in animals, which are then transferred to humans when we eat foods from these animals like meat or milk.

  • Evolution of bacteria. Currently, bacteria are evolving to develop resistance to antibiotics faster than we can create new medicines to treat them, leaving doctors with fewer tools in their arsenal to fight against bacteria.

  • Overuse of antibiotics. Many people take antibiotics when it isn’t medically necessary. “Most upper respiratory tract infections, whether it’s a sore throat or sinus symptoms, are due to viruses and will get better without the use of antibiotics,” Ross said.

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