Antibiotic Reduction Campaigns Do Not Necessarily Reduce Resistance
Programs’ success depends on which antibiotics are targeted (July 29)
Antibiotic use — and misuse — are the main drivers for the selection of antibiotic-resistant bacteria. This has led many countries to implement interventions designed to reduce overall antibiotic consumption. Using methicillin-resistant Staphylococcus aureus (MRSA) as an example, investigators in France warn that simply reducing antibiotic consumption does not necessarily reduce resistance.
The new research was published online in Antimicrobial Agents and Chemotherapy, a publication of the American Society for Microbiology (ASM).
The success of antibiotic reduction programs depends on which antibiotics are reduced, because some select more strongly for resistance than others, says lead investigator Dr. Laura Temime. For example, in the case of S. aureus, reducing the use of clindamycin and methicillin leads to decreased resistance, whereas reducing the use of penicillins does not, since most S. aureus organisms, including MRSA, are already resistant to penicillin.
In addition, efforts to reduce antibiotic use must be coordinated between hospitals and the community, since either can feed resistant bacteria into the other, undermining reduction efforts, Temime says.
In 2002–2003, a national program reduced antibiotic use in France by 10%. However, the program fell short of its full potential for reducing resistance because it failed to target antibiotics that generate the most resistance, according to Temime. She and her colleagues developed a mathematical model of MRSA circulation, which correctly simulated that reduction post facto. They then performed a number of simulations of reductions in antibiotic use, which demonstrated the complexities of reduction efforts.
Their research shows that class-specific changes in antibiotic use, rather than overall reductions, need to be considered in order to achieve the greatest benefit from antibiotic reduction campaigns.
“This underlines the importance of generating surveillance data on both antibiotic class-specific changes in antibiotic use and antibiotic resistance in the years following an antibiotic reduction campaign. We believe that this research may help health policy makers and physicians in the design of more efficient antibiotic-reduction campaigns,” Temime says.
Source: ASM; July 29, 2013.