French and American researchers are testing new methods of fighting bacteria that have developed antibiotic resistance. Scientists have published an article describing the new therapy in the journal Disease Models & Mechanisms.
Bacterial resistance to antibiotics can be innate (intrinsic) and acquired. Congenital (natural) resistance is characterized by the absence of the target of antibiotic action in microorganisms or the inaccessibility of the target due to initially low permeability or enzymatic inactivation. Antibiotic resistance is one of the most serious threats to human health, food security and development today, according to the UN. Scientists are constantly looking for new ways to solve the problem, often using non-standard methods.
In the new method, scientists used bacteriophage viruses along with antibiotics already used in drug practice to treat resistant infections caused by Mycobacterium abscessus.
Mycobacterium abscessus, a relative of the bacteria that cause tuberculosis and leprosy, is responsible for particularly serious damage to human lungs and can be resistant to many standard antibiotics, making infections difficult to treat. They are not only dangerous, but also common soil and water contaminants. Nevertheless, bacteria are vulnerable to viruses of natural origin – bacteriophages: for each type of bacteria there is a unique virus that destroys it.
Earlier, American scientists identified one bacteriophage known as “Muddy” that effectively kills bacteria in a petri dish. To avoid testing the virus in humans, the scientists used zebrafish. They are a model organism in developmental biology and are known in the English-language literature as zebrafish.
After infecting them with Mycobacterium abscessu, the scientists observed the fish for 12 days. The biologists found that the zebrafish developed a serious infection with abscesses and had a high mortality rate; only 20% of the animals survived.
The team then tested how well the infected fish recovered when the antibacterial bacteriophage Muddy was injected for five days. This time, the fish had much fewer severe infections, an increased chance of survival (40%), and there were fewer abscesses that the fish suffered during a severe infection.
Then scientists began to treat infected fish not only with a virus, but also with an antibiotic known as rifabutin. The survival rate of fish has risen sharply to 70%.
Ultimately, scientists hope that this method can be used to treat people as well.