One of the most pressing global health issues is the problem of resistance to antimicrobial drugs. Antimicrobial resistance contributes to the uncontrolled increase in the number of pathogenic microorganisms, which leads to higher levels of infectious diseases.
Antimicrobial resistance complicates the prevention and treatment of diseases, caused by bacteria, viruses, fungi and parasites. More and more countries are beginning to focus on this issue, as it poses a threat not just to countries on the individual level, but to the whole world.
For this reason, the global action plan on antimicrobial resistance was adopted in May, 2015 at the 68 World Health Assembly.
One of the five strategic objectives of the plan is to strengthen the evidence base through global surveillance and researches in the field of antimicrobial resistance. According to statistics, the number of antibacterial drugs in recent years has increased, along with which antimicrobial resistance has also shown a considerable growth.
A number of factors contributes to the growth of drug resistance level. As pointed out by the WHO in 10 facts on antimicrobial resistance, the use of sub-therapeutic doses of antibiotics in animal and poultry feed contributes to antibiotic resistance increase.
The other factors, contributing to antimicrobial resistance also include weak surveillance systems, poor infection control and prevention. Great concern with the issue of drug resistance development served as the basis for the global antimicrobial resistance researches, carried out by the WHO in collaboration with member states.
In 2014, the WHO presented a paper “Antimicrobial resistance: Global report on surveillance in 2014”, which identified the key areas of the fight against antimicrobial resistance. The main attention was paid to the antibacterial resistance in the treatment of such diseases, as malaria, tuberculosis and HIV.
It should be noted that modern medicine distinguishes two types of antimicrobial resistance:
– natural (intrinsic)
The appearance of acquired resistance in a microorganism is not always associated with the reduction in clinical efficacy of antibacterial drugs. Such antimicrobial resistance develops under the influence of various environmental factors. As a result of this influence, the microbe acquires new properties or loses its old qualities.
The drug resistance often develops as a result of the microbial strains evolution and misuse of antimicrobial drugs. The evolution of resistant strains is considered to be a natural phenomenon that occurs in faulty reproduction or mutations of microbes.
Reasons for the development of antimicrobial resistance are diverse, the most important being irrational and misguided use of antibiotic drugs, among which are:
– wrong drug choice
– unjustified prescription of antibiotics
– wrong choice of dosage regimen
– unreasonably long use
Natural (intrinsic) antimicrobial resistance is characterized by the inaccessibility of antimicrobial agent for affecting the target, due to the enzymatic activation or the primary low permeability. It often happens that the microorganism totally lacks the target for the effect of the antimicrobial drugs.
Researches have shown that antibiotics are clinically ineffective in the presence of the natural resistance in microorganisms.
The mechanism of antimicrobial resistance is often based on the modification of the antibiotic action target, antibiotic excretion from microbial cells, formation of metabolic shunt, antibiotic inactivation, violation of permeability in microbial cells outer structure.
It should be noted that various microorganisms are characterized by their mechanisms of resistance development. Researchers recommend using antibiotics with a specific range of action after determining sensitivity to them for reducing antimicrobial resistance in humans.
Patients should strictly comply with the recommended dosage and treatment duration. Rotation of antimicrobial drugs is also recommended to reduce the risk of drug resistance.
Recent researches have shown that the rotation of antimicrobials (e.g. using antibiotics with different mechanisms of action) reduces the incidence of infections.
To prevent antimicrobial resistance, it is necessary to adhere to the following principles:
use antibiotics with a narrow spectrum of action
use the parenteral route of antimicrobials administration
minimize local administration of antimicrobials
carry out therapy with the maximum doses until the infection is completely overcome
limit the use of drugs, intended for humans, in the food industry and the veterinary
periodically assess the type of pathogen and resistance of microbial strains for the purpose of effective antimicrobials selection.