From diseases caused by antibiotic-resistant microorganisms die each year up to 700 thousand people. By mid-century this figure could rise to ten million, say UN experts. This writes RIA “Novosti”.
Attempts to strictly regulate the sale of antimicrobials to limit their use in agriculture, while the effect was not brought. Superbugs are rapidly spreading throughout the world, and scientists discover new organisms, against which antibiotics are powerless, even the last reserve. What dangers threaten humanity in 2020?
Arctic insensitivity to antibiotics
In February 2019 British, American and Chinese researchers found a bacteria found in the Arctic, the gene of antibiotic resistance blaNDM-1. The germs that have it in their DNA to be immune to virtually all beta-lactams are the most numerous and widespread group of antibiotics.
For the first time blaNDM-1 was described in 2008 in a clinical setting, in 2010 it was found in India. By estimations of authors of the work, within five years he reached a remote area of West Spitsbergen, probably together with migratory birds wintering in the British Isles, or people. The flora of the archipelago threat gen, most likely, blew foxes who love to dig in garbage near human settlements.
Scientists took soil samples in the Bay area Kongsfjorden allocated out of the DNA of microbes and identified 131 gene of antibiotic resistance (antibiotic resistance). Thirty-nine qualified as autochthonous, that is local, only in stress conditions (for example, at high levels in the soil of heavy metals). But others, apparently, are imported, including blaNDM-1.
The authors did not expect that genes for antibiotic resistance spread so rapidly.
Lightning-fast exchange of threat genes
About the same time German, Danish and Brazilian microbiologists have proposed a possible explanation for such a rapid growth in the number of microorganisms that are resistant to several groups of antibiotics.
For 34 days the fish Piaractus mesopotamicus, grown in aquaculture conditions, given food with antibiotic florfenicol. Then took samples of gut bacteria from the digestive tract of animals. As expected, almost all organisms contain genes enabling them to resist florfenicol. But it turned out that bacteria exchange genes is not useful by using a plasmid — isolated from the chromosome DNA molecules, as previously thought, but through viruses and mobile genetic elements (so-called jumping genes).
The researchers note that it’s a major shift in the distribution model of antibiotic resistance genes. Most likely, the antimicrobial resistance in bacteria is transferred much faster.
African bacterium with superpowers
In September, 2019 in the Republic of Congo has opened a new Supermicro — neposedlivogo Salmonella, characterized by high resistance to antibiotics. Against this variant of the bacterium impotent Ceftriaxone and the cephalosporin antimicrobial drugs in the second line, is usually recommended for the treatment of severe intestinal infections. Also Salmonella were sensitive to azithromycin.
In addition, the researchers found that this strain has lost the ability to form biofilms and survive on different culture media. In other words, he has adapted to the human body. In his DNA was the gene encoding the protein of the bacterial flagellum. Typically human immune cells react on him, and so now the Salmonella is harder to detect and destroy.
The researchers suggest that extensively drug resistant Salmonella emerged in Congo in 2004 at the latest and has already spread at least in three cities of the country.
New Supermicro in the heart of Europe
In October, French researchers announced that one of the strains Pseudomonas aeruginosa (Pseudomonas aeruginosa) failed combined antibiotic cephalothin-tazobactam. This is one of the products of the last reserve in the treatment of severe gram-negative nosocomial infections. It can cause serious side effects, so is used only in extreme cases, when other means do not help.
Supermicro found in a French child, twice undergoing surgery on the liver and for two years suffered from recurrent infections caused by Pseudomonas aeruginosa. Doctors prescribed cephalothin-tazobactam. And after 22 days in the patient found Pseudomonas aeruginosa that is sensitive to the antibiotic.
Having studied the genomes of several dozen of its models, the researchers found that antibiotic resistance is the result of a single mutation in a gene that encodes an enzyme cephalosporinase.
With the disease fought 2.5 years. It became clear that, acquiring immunity to antibiotics, Pseudomonas aeruginosa was losing protection from the other medicines. So, it is likely to win some superbugs with older drugs, say the authors.