Bacteriophages suppress antibiotic resistance
"Kind" bacteriophages helped overcome the resistance of bacteria to antibiotics
Researchers have come up with a scheme that allows you to destroy antibiotic-resistant bacteria. To kill microorganisms, scientists used bacteriophages, which do not kill bacteria, but edit their genome, allowing them to then destroy bacterial cells with conventional drugs.
An increasing number of bacteria are becoming resistant to antibiotics: microorganisms accumulate mutations that make them insensitive to the effects of drugs. Moreover, microorganisms transmit to each other genes that provide resistance to drugs by horizontal transfer. One of the ways to solve this problem, which seriously threatens the safety of people, is the use of bacteriophages, that is, viruses that infect bacterial cells.
The use of bacteriophages is complicated by problems with the delivery of viruses to bacterial-affected tissues, as well as the fact that bacteria are able to transmit genes to each other that provide resistance to viruses. Researchers from the Sackler School of Medicine in Tel Aviv and the University of California at Berkeley have invented a way to effectively use bacteriophages to destroy the protective mechanism of bacteria. The scientists' article was published in the journal Proceedings of the National Academy of Sciences: Yosef et al., Temperature and lytic bacteriophages programmed to sensitize and kill antibiotic-resistant bacteria. (The results of the work are popularly described in The Scientist: Targeting Antibiotic-Resistant Bacteria with CRISPR and Phages – VM.)
In order to solve the problem, the researchers used the bacteriophage lambda, which normally does not destroy bacterial cells. All phages, when infected, "inject" their DNA into a bacterial cell, and the phage "sent" by scientists carried specially modified sections. The researchers added the so-called CRISPR-Cas genetic editing system to the phage genome, thanks to which certain genes can be purposefully removed from the genome of an infected bacterium. In this case, the genes that make microorganisms resistant to antibiotics were removed. At the same time, the lambda GM phage made bacteria resistant to more aggressive bacteriophages (they are called lytic), which cause the bacterial cell to rupture.
Scientists propose the following scheme for fighting bacteria. First, bacteria living, for example, on the skin, are infected with the lambda GM phage, making them resistant to lytic phages and at the same time sensitive to antibiotics. Then lytic phages are applied to the skin, which kill those microorganisms that were not infected with the first phage. Finally, the remaining bacteria – and these are mainly antibiotic–resistant microorganisms - are destroyed with the drug.
Scientists believe that the method they invented to suppress the resistance of bacteria to drugs will be an effective tool in the treatment of many diseases and will allow to bypass the increasingly widespread resistance to antibiotics.
Portal "Eternal youth" http://vechnayamolodost.ru19.05.2015