Associations between Sputum Microbiome and Antibiotic Allergy in Patients with Cystic Fibrosis

Abstract

RATIONALE: We previously demonstrated associations between antibiotic allergy and prevalence of microbes such as methicillin resistant staphylococcus aureus and vancomycin resistant enterococcus in the general population. We hypothesized that the high prevalence of antibiotic allergy in Cystic Fibrosis (CF) could affect their sputum microbiome. METHODS: An IRB approved, retrospective analysis was performed on 271 cystic fibrosis patients seen at our medical center from 2001-2012. Sputum culture results (obtained in 2012) were analyzed in 201 of these subjects. RESULTS: Chart-reported antibiotic allergy was present in 35% of CF patients compared to 11% of the general population. The most common reactions were penicillin (48.4%), cephalosporins (36.8%), vancomycin (24.2%), and fluoroquinolones (11.6%).We identified numerous organisms that were cultured at different frequencies in antibiotic-allergic vs. non-allergic CF patients. Six pathogens were present at >two fold higher rates in patients with antibiotic allergy: Alcaligenes xylosoxidans, methicillin-resistant Staphylococcus aureus, Stenotrophomonas (Xanthomonas) maltophilia, methicillin-sensitive Staphylococcus aureus, mucoid Pseudomonas aeruginosa, and non-mucoid Pseudomonas aeruginosa. There were seven bacteria that cultured at >two fold less rates in antibiotic allergic patients: Enterobacter asburiae, Pantoea (Enterobacter) agglomerans, Streptococcus pneumoniae, Klebsiella oxytoca (extended-Spectrum Beta-lactamase), Klebsiella pneumoniae, Moraxella catarrhalis, and Pseudomonas fluorescens putida group. CONCLUSIONS: Differences in sputum microbes in antibiotic allergic and non-allergic subjects may have important implications for disease course and antibiotic treatment. Future work is needed to understand the nature of the relationship between microbiome and antibiotic allergy.