Antibiotics are used to treat bacterial infections. However, its overuse has lead to antibiotic resistance, meaning that some antibiotics have reduced or no activity when used to treat certain bacteria. Antibiotic resistance threatens the effective prevention and treatment of an ever-increasing range of infections caused by bacteria.
A new study has revealed a different but simple way of administering antibiotics that may improve treatment of bacterial infection and also reduce the risk of the bacteria becoming resistant to antibiotics, thus maintaining the long-term effectiveness of the drugs. Researchers now recommend using alternating doses of antibiotics at low dosages. This new technique is called 'sequential treatments'.
Robert Beardmore from the University of Exeter in Britain and lead author of this study said, "Our study finds a complex relationship between dose, bacterial population densities and drug resistance. The research indicates that drug treatments with two antibiotics can be designed to kill bacteria at dosages that would ordinarily cause rapid development of drug resistance and sustained bacterial growth, when administered alone or in combination. As we demonstrate, it is possible to reduce bacterial load to zero at dosages that are usually said to be sub-lethal."
Researchers used a test tube model of a bacterial infection to show that even in bacteria that already harbor drug resistance genes, sequential treatments could deal with the bacteria even when much higher doses of single drugs or mixtures of two drugs failed to do so. They also discovered that although sequential treatments did not suppress the rise of all drug resistant mutations in the bacteria, one drug would 'sensitize' the bacteria to the second drug, and therefore reduce the risk of resistance occurring.
The findings are published in PLOS Biology