The resistance to antibiotics in superbacteria of greater interest for man tends to stabilize after an initial increase period.
The resistance of bacteria to antibiotics tends to stabilize in time after an initial increase phase. This is suggested by a study that could help understand the long -term dynamics of the phenomenon, indirectly associated with almost 5 million deaths per year. Scientists from the University of Lausanne have ascertained that the main species of superbatter dangerous for man reach a plateau – a situation of stasis or plan after the initial surge – in their ability to increase the resistance to antibiotics after a couple of decades.
Live evolution. The researchers analyzed drug resistance in over 3 million bacterial samples collected in 30 European countries from 1998 to 2019. In total, the trajectories of antibiotic resistance in 887 bacterium-pharmo-paese combinations were considered for eight species of bacteria relevant to public health, such as it Streptococcus pneumoniaelo Staphylococcus aureustheEscherichia coli And it Klebsiella Pneumoniae. The choice to consider a long period of time responds to the need to study the evolutionary dynamics of antibiotic-resistance.
Growth and stall. The resistance rates of these bacteria to the various antibiotics in the different countries have not been able to increase indefinitely, that is, “indefinitely”, in the 20 years considered. Most of the interactions showed achieve a “flattening” phase in the growth of resistance phenomenaafter an initial surge phase. It means that a continuous increase in antibiotic resistance in the main bacterial species is not inevitable, an important aspect for those who monitor the evolution of this phenomenon.
Recall that, in order for a public health problem to occur, it is not necessary that a bacterial species be resistant to a certain antibiotic in all cases. For example, the antibiotic ciprofloxacin It is no longer recommended in the United States for the treatment of infections from Neisseria Gonorrhoeaa Since 2007 – and at that moment the frequency of resistance of the bacterium to the antibiotic was less than 15%.
Antibiotics count, but there is more. The use of antibiotics has contributed to the speed with which the resistance levels have stabilized, as well as to the variability in resistance rates in the different countries. «When we have examined the dynamics of antibiotic resistance in many important bacterial pathogens throughout Europe and in recent decades, we have often found that the frequency of the resistance initially increases and then stabilizes at an intermediate level. The consumption of antibiotics in the country explained both the speed of the initial increase and the stabilization level »explains Francois Blanquart, the evolutionary biologist who led the study.
However, the association between changes in drug resistance and the use of antibiotics was weak: therefore there must also be some other factors involved and still to be clarified.
