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A4924 - Non Concordance Between Sputum and Pulmonary Explant Fragments Culture in Patients with Cystic Fibrosis After Lung Transplantation
Author Block: R. A. Athanazio1, S. Z. Rached1, R. Stelmach1, A. Cukier1, R. M. Carvalho-Pinto1, A. N. Costa1, F. L. Fernandes2, M. N. Samano1, R. H. Teixeira1, S. V. Campos1; 1Divisão de Pneumologia, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, São Paulo, Brazil, 2Divisão de Pneumologia, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil.
Rationale: Patients with cystic fibrosis (CF) exhibit changes in the usual flora of the lungs and are commonly infected by pathogenic microorganisms. However, dissociation between clinical response to antibiotics and microbiological profile in sputum surveillance cultures is commonly seen. The aim of this study was to compare the microbiological profile of sputum culture in patients with CF with explant samples of 5 pulmonary different lobes after lung transplantation. Methods: Sputum samples from CF patients were collected immediately before lung transplantation. Samples of bronchial secretion were collected by a syringe through the main bronchus of pulmonary explants. Lung tissue fragments of the 5 pulmonary lobes were also sent to microbiological evaluation. All materials were evaluated through aerobic, fungi and mycobacteria cultures. Microbiological surveillance was performed with programmed broncoalveolar lavages according to institutional protocol after lung transplantation (1, 3, 6 and 12 months after surgery). Results: From 2016, nine CF patients were included in the study (5 female / 4 male). Mean age was 21.1 years, varying from 13 to 38. Sputum cultures previous to lung transplantation demonstrated Pseudomonas aeruginosa as the most common bacteria isolated (7/9 patients), followed by Staphylococcus aureus (3/9 patients) and Achromobacter sp and Enterobacter cloacae complex (each one in 1/9 patients). A high concordance between bronchial secretion and sputum culture was observed (7/9 patients), although only 1 patient presented microbiological concordance between all lobe fragments cultures and sputum (Achromobacter sp). A high number of microorganisms not identified in their corresponding sputum had grown in lung fragments cultures such as Stenotrophomonas maltophilia, S. aureus, Candida albicans, Candida parapsilosis and Escherichia coli. During follow-up, only two patients were re-colonized by bacteria present in cultures of respiratory secretions prior to transplantation, both of which were P. aeruginosa (one after 6 and the other after 12 months of the procedure). Conclusion: A high non-concordance rate between sputum and pulmonary explant fragments culture in patients with CF after lung transplantation was shown in this study. Our data emphasize the heterogeneity and differences in lung involvement of CF patients. These regional features may justify differences in clinical outcomes in individuals with similar sputum culture. In addition, inadequate clinical response to standard antibiotic therapy guided by sputum culture in CF subjects should raise the suspicion for infection by different microorganisms in the more distal airways.