Restrictive Antibiotic Policies May Decrease Resistance in Nonfermenters

A team of investigators conducted a meta-analysis to determine the effect of restricting the use of specific antibiotic classes on the prevalence of resistant bacterial pathogens.

Although restricting carbapenems or third-generation cephalosporins did not lead to a decreased prevalence of antibiotic resistance among Enterobacterales, nonfermenters, or Gram-positive bacteria, reducing the use of fluoroquinolone and piperacillin-tazobactam was found to decrease resistance in nonfermenters among hospitalized adults, according to the results of a systematic review and meta-analysis published in Open Forum Infectious Diseases. The study authors suggested that a multifactorial intervention, not just a single intervention of restrictive antibiotic use, may be a more effective tool to combat antimicrobial resistance in hospital settings.

This meta-analysis included 15 international observational studies that reported the number of isolates tested for Enterobacterales, nonfermenters, or Gram-positive bacteria in a hospital or intensive care unit setting. The analysis focused on 3 restricted antibiotic classes (carbapenems, fluoroquinolones, and third-generation cephalosporins) and 2 nonrestricted antibiotics (piperacillin-tazobactam and first- and second-generation cephalosporins).

Most studies reported resistance prevalence in Enterobacterales and nonfermenters for both restricted and nonrestricted antibiotics. Overall, there was a low quality of evidence for the studies, and most showed a high degree of heterogeneity for most antibiotic-pathogen combinations, with the following exceptions: piperacillin-tazobactam/nonfermenters, piperacillin-tazobactam/Enterobacterales, and fluoroquinolones/Enterobacterales (I2=0% for all).

When comparing the pooled odds of having resistance during the postintervention vs preintervention period, there was noted to be a 23% and 19% decrease in resistance to nonfermenters after restricted use of fluoroquinolones (odds ratio [OR], 0.77; 95% CI, 0.62-0.97) and piperacillin-tazobactam (OR, 0.81; 95% CI, 0.72-0.92), respectively.

A sensitivity analysis excluding studies with fewer than 50 bacteria yielded similar results. In addition, “There was no evidence of publication bias for any of the antibiotic-pathogen combinations,” the study authors noted.

Limitations of this study were an exclusion of grey literature and focus on just 3 restricted antibiotic classes. The studies varied in publication date (1985 to 2020) and antibiotic-prescribing practices, and rates of resistance had changed dramatically during that period.

“…restrictive antibiotic policies as a single intervention might not be an effective tool to achieve decreases in the prevalence of resistance in hospitalized adults,” the authors stated. High-quality studies are needed “…to explore alternative interventions that could bring way to reduced prevalence of antimicrobial resistance,” the authors concluded.


Schuts EC, Boyd A, Muller AE, Mouton JW, Prins JM. The effect of antibiotic restriction programs on prevalence of antimicrobial resistance: a systematic review and meta-analysis. Open Forum Infect Dis. Published online February 13, 2021. doi:10.1093/ofid/ofab070