Macrolide therapy is associated with clinical failure in some cases of acute exacerbation of chronic bronchitis (AECB). While the most likely reason for failure is resistant pathogens, there is little reliable microbiologic information in these patients. We have previously demonstrated that protected brush sample (PBS) provides the most reliable culture information in AECB (Baughman, R. P. et al. J Bronchology 2000;7:221-5). We used this technique to evaluate patients who failed azythromycin treatment for AECB.
Patients with a history of COPD and a clinical course consistent with AECB who had been treated with azythromycin and had persistent symptoms were evaluated. All patients underwent bronchoscopy with a PBS taken from the lower respiratory tract. The specimen was sent for semi-quantitative cultures. Patients were then treated with five days of moxifloxacin and repeat bronchoscopy was performed. No patient had been hospitalized in the prior six months.
Thirteen patients have been studied. Eleven patients had one or more bacteria identified in the initial PBS specimen. Seven patients had at least one bacteria growing at >1000 colony forming units (cfu)/ml from the initial PBS specimen. S. aureus was isolated in five (38%) of the initial PBS cultures. The S. aureus was sensitive to oxacillin in 4/5 case, ciprofloxacin 4/5 cases, and trimethoprim/sulfamethoxazole in 5/5 cases. Only one S. aureus was sensitive to erythromycin. After five days of moxifloxacin, no respiratory pathogens were identified in the repeat PBS specimen.
Significant bacterial infection was identified in patients with persistent symptoms despite azythromycin therapy for their AECB. Among the pathogens was S. aureus. Treatment with a moxifloxacin was associated with clearance of the micro organism.
Patients with repeated AECB infections and previously treated with macrolide therapy are at risk for multi drug resistant bacteria, including S. aureus.
Robert Baughman, Grant monies (from industry related sources) Bayer/Schering Plough; Consultant fee, speaker bureau, advisory committee, etc. Bayer/Schering Plough.