A Multicenter Evaluation of Trends in Antimicrobial Resistance Among Isolates From Adults in the United States.

BACKGROUND

Management of pneumococcal disease is complicated by high rates of antimicrobial resistance (AMR). This study assessed AMR trends for Streptococcus pneumoniae isolates from adults with pneumococcal disease.

METHODS

From January 2011 to February 2020, we evaluated 30-day nonduplicate isolates from 290 US hospitals (BD Insights Research Database) from adults (≥18 years) in inpatient and outpatient settings. Isolates were required to have ≥1 AMR result for invasive (blood, cerebrospinal fluid/neurologic) or noninvasive (respiratory or ear/nose/throat) pneumococcal disease samples. Determination of AMR was based on facility reports of intermediate or resistant. Descriptive statistics and generalized estimated equations were used to assess variations over time.

RESULTS

Over the study period, 34 039 isolates were analyzed (20 749 [61%] from noninvasive sources and 13 290 [39%] from invasive sources). Almost half (46.6%) of the isolates were resistant to ≥1 drug, and noninvasive isolates had higher rates of AMR than invasive isolates. Total isolates had high rates of resistance to macrolides (37.7%), penicillin (22.1%), and tetracyclines (16.1%). Multivariate modeling identified a significant increasing trend in resistance to macrolides (+1.8%/year;  < .001). Significant decreasing trends were observed for penicillin (-1.6%/year;  < .001), extended-spectrum cephalosporins (ESCs; -0.35%/year;  < .001), and ≥3 drugs (-0.5%/year;  < .001).

CONCLUSIONS

Despite decreasing trends for penicillin, ESCs, and resistance to ≥3 drugs, AMR rates are persistently high in isolates among US adults. Increasing macrolide resistance suggests that efforts to address AMR in may require antimicrobial stewardship efforts and higher-valent pneumococcal conjugate vaccines.