Scientists found Escherichia coli bacteria resistant to colistin, a last resort antibiotic.This is the second case in the United States, according to a study published on Monday. The recent case was identified in a patient that had surgery at a New York hospital in 2015. The study was posted online in a journal of the American Society for Microbiology, in Antimicrobial Agents and Chemotherapy, and the results of the study are concerning.

An evolution of bacteria resistant to all antibiotics known worldwide as E. coli is a possibility. The first case of bacteria resistant to colistin in the U.S was found in Pennsylvania, after its identification in China last year, according to The New York Times. The case in Pennsylvania involved a woman that carried a strain of E. coli bacteria with a gene resistant to colistin, the antibiotic that it is used by doctors as a last resort when no other antibiotic works.

In both cases, the bacteria carried the mcr-1 gene, which allows bacterias and other organisms to withstand colistin. Image Credit: Stat News
In both cases, the bacteria carried the mcr-1 gene, which allows bacteria and other organisms to withstand colistin. Image Credit: Stat News

The current study is part of the worldwide SENTRY Antimicrobial Surveillance Program, and it analyzed 13,526 E. coli and 7,480 Klebsiella pneumonia clinical strains collected in 2015 from hospitals in Asia, Latin America, Europe and North America. The results showed that 390 E. coli strains, which represent 1.9 percent of the sample, were resistant to colistin and 19 of these isolates tested positive for mcr-1. Regarding the Klebsiella pneumonia, they were not resistant to the antibiotic.

The 19 resistant isolates were from 10 different countries, and only one came from the U.S., the New York case. The other mcr-1 resistant strains were found in Belgium (1), Germany (5), Italy (4), Spain (3), Poland (1), Russia (1), Hong Kong (1), and Malaysia (1), Medscape Medical News reports.

Medscape also says that the authors of the research informed that they still do not know if the mcr-1 gene is encoded in the bacterial chromosome or a plasmid. But if it is codified in a plasmid, the bacteria can quickly pass plasmids to others strains and transfer the resistance gene.

The Pennsylvania woman E. coli bacteria acquired the colistin-resistance gene through plasmid

The Washington Post says that the gene has been found in humans and animals as well, making Health officials and infectious-disease experts around the world start a state of alert. The gene was proved to come from 3 different continents, and this means that it could be spreading. Gene mcr-1 could also transfer to other bacteria already resistant to all antibiotics.

Dr. Mariana Castanheira, Ph. D., and director of molecular and microbiology at JMI Laboratories in North Liberty, Iowa, along her colleagues, develop the study that researched the mcr-1 gene. Medscape Medical News says that Dr. Castanheira stated regarding the results that the gene was detected on food livestock and raw meat, which she says is also concerning.

Dr. Frank Esper, a pediatric infectious disease specialist at University Hospital Case Medical Center, stated that the report is alarming but not surprising for experts in the subject. He told ABC News that it is a wake-up call. He added that it is only a matter of time for the increase of cases of bacteria resistant to colistin, and that next thing will know is that we do not have the means to fight the superbug.

Dr. William Schaffner, who is an infectious disease expert at Vanderbilt University Medical Center, said that health experts have always fear that there will be a rise in drug-resistant bacteria because there has been few antibiotic research in the previous years. Image Credit: NBC News
Dr. William Schaffner, who is an infectious disease expert at Vanderbilt University Medical Center, said that health experts have always fear that there will be a rise in drug-resistant bacteria because there has been few antibiotic research in the previous years. Image Credit: NBC News

To minimize the risks to create antibiotic-resistant bacteria, Dr. Schaffner stated that three things must be done, says ABC News. The first thing is to prescribe antibiotics much more prudently because the use of antibiotics create resistance in the bug if it is wrongly used. For example, when this kind of drug is prescribed for three days and the patients only takes it for one day, the bacteria can create a resistance to the antibiotic. Secondly, Schaffner says that antibiotics cannot be used as freely as they are employed in the food industry. And third, he stated that it is necessary to energize and create environments so pharmaceutical companies can start developing new antibiotics.

This third point is because the pharmaceutical industry has little incentive to test new antibiotics, and Dr. Schaffner highlights the need for the development of new medicines to be prepared in case of a spike of antibiotic-resistant bacteria outbreaks in the next few years, ABC News says. He added that creating new antibiotics is a long-term commitment, between 5 to 10 years. David Hyun, a senior officer at Pew’s Antibiotic Resistance Project, said that the results showed in the study are significant because they underscore the need for more research and the improvement of surveillance to registered the reach of the widespread resistance and how patients are impacted.

U.S. Hospitals are not equipped to do testing for mcr-1

According to Mike Bell, deputy director of healthcare quality promotion at the Centers for Disease Control and Prevention(CDC), testing for mcr-1 requires more molecular biology analysis that hospital cannot perform because they do not have the equipment. This is because mcr-1 are rarely needed.

But to evaluate the mcr-1 presence, the CDC plans to establish seven regional laboratories this fall with the capacity to do testing for a broad range of antimicrobial resistance.

Source: Medscape