Nabriva Therapeutics plc announced the publication of a study documenting the high rates of macrolide-resistant Streptococcus pneumoniae throughout the United States. The study entitled, A Multicenter Evaluation of the Prevalence and Regional Variation in Macrolide Resistant S. pneumoniae in Ambulatory and Hospitalized Adult Patients in the U.S. was published this month in Open Forum Infectious Diseases (OFID), and demonstrated that macrolide resistance in S. pneumoniae is greater than 25 % in most regions of the country and 39.5 % overall. An accompanying editorial, authored by Daniel Musher, M.D., was also published in same issue of OFID. The retrospective cohort study assessed 3,626 patients with a positive S. pneumoniae blood or respiratory culture evaluated between October 2018 and September 2019 at 329 hospitals in the BD Insights Research Database across nine U.S. Census geographic regions. Macrolide resistance was observed in 47.3 % of S. pneumoniae obtained from respiratory cultures, and 29.6 % from blood cultures. While the overall rate of macrolide resistance was 39.5 %, macrolide resistance in respiratory isolates was =25% in all regions of the U.S. In addition, higher rates of macrolide resistance were seen among ambulatory patients (45.3 %) as compared with inpatients (37.8 %). Macrolide-resistant S. pneumoniae is designated as a serious public health threat according to the Centers for Disease Control and Prevention (CDC). S. pneumoniae is the leading cause of community-acquired bacterial pneumonia (CABP), a lung infection and the most common type of pneumonia that occurs outside of hospitals or other health care facilities. According to the CDC, S. pneumoniae causes 900,000 infections and 3,600 deaths annually. Joint guidance from the Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) for the treatment of CABP recommend that macrolide antibiotics only be used if local pneumococcal resistance is less than 25 %.