The Effect of Macrolide Resistance on the Presentation and Outcome of Patients Hospitalized for Streptococcus pneumoniae Pneumonia.

RATIONALE There are conflicting reports describing the effect of macrolide resistance on the presentation and outcomes of patients with Streptococcus pneumoniae pneumonia. OBJECTIVES We aimed to determine the effect of macrolide resistance on the presentation and outcomes of patients with pneumococcal pneumonia. METHODS We conducted a retrospective, observational study in the Hospital Clinic of Barcelona of all adult patients hospitalized with pneumonia who had positive cultures for S. pneumoniae from January 1, 2000 to December 31, 2013. Outcomes examined included bacteremia, pulmonary complications, acute renal failure, shock, intensive care unit admission, need for mechanical ventilation, length of hospital stay, and 30-day mortality. MEASUREMENTS AND MAIN RESULTS Of 643 patients hospitalized for S. pneumoniae pneumonia, 139 (22%) were macrolide resistant. Patients with macrolide-resistant organisms were less likely to have bacteremia, pulmonary complications, and shock, and were less likely to require noninvasive mechanical ventilation. We found no increase in the incidence of acute renal failure, the frequency of intensive care unit admission, the need for invasive ventilatory support, the length of hospital stay, or the 30-day mortality in patients with (invasive or noninvasive) macrolide-resistant S. pneumoniae pneumonia, and no effect on outcomes as a function of whether treatment regimens did or did not comply with current guidelines. CONCLUSIONS We found no evidence suggesting that patients hospitalized for macrolide-resistant S. pneumoniae pneumonia were more severely ill on presentation or had worse clinical outcomes if they were treated with guideline-compliant versus noncompliant regimens.