title: Intravenous antibiotics reduce the presence of Aspergillus in adult cystic fibrosis sputum.
abstract: BACKGROUND
  Pseudomonas aeruginosa and Aspergillus fumigatus frequently co-colonise the airways of patients with cystic fibrosis (CF). This study aimed to assess the impact of short-term administration of intravenous antipseudomonal antibiotics during CF exacerbations on the presence of Aspergillus.
  
  
  METHODS
  Pre- and post-antibiotic sputum samples from 26 adult patients with CF and chronic Pseudomonas colonisation were analysed for the presence of Aspergillus by fungal culture, real-time PCR and galactomannan antigen (GM). Lung function (forced expiratory volume in 1 s and forced vital capacity % predicted) and blood levels of total IgE, specific A fumigatus IgE and specific A fumigatus IgG were measured at the start and end of antibiotics. Respiratory viral real-time PCR and bacterial community profiling using ribosomal intergenic spacer analysis (RISA) were performed to estimate concurrent changes in the lung microbiome.
  
  
  RESULTS
  Aspergillus PCR and GM were more sensitive than culture in detecting Aspergillus species (culture 8%, GM 31%, PCR 77%). There was a significant decline in the presence of Aspergillus, measured both by PCR and GM index, following antibacterial therapy (PCR: median increase in crossing threshold 1.7 (IQR 0.5-3.8), p<0.001; GM: median fall in GM index 0.7 (IQR 0.4-1.6), p=0.016). All patients improved clinically with a significant increase in lung function (p<0.0001). RISA community analysis showed large changes in bacterial community similarity in 67% of patients following antibiotics. Viral RT-PCR demonstrated the presence of a concurrent respiratory virus in 27% of patients.
  
  
  CONCLUSIONS
  Intravenous antibiotics targeting Pseudomonas during CF pulmonary exacerbations have a negative impact on the presence of Aspergillus in sputum samples.
authors.affiliation: National Aspergillosis Centre, University Hospital of South Manchester, Manchester, UK. caroline.baxter@manchester.ac.uk
authors.forename: Caroline G
authors.initials: CG
authors.lastname: Baxter
authors.forename: Riina
authors.initials: R
authors.lastname: Rautemaa
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Jones
authors.forename: A Kevin
authors.initials: AK
authors.lastname: Webb
authors.forename: Matthew
authors.initials: M
authors.lastname: Bull
authors.forename: Eshwar
authors.initials: E
authors.lastname: Mahenthiralingam
authors.forename: David W
authors.initials: DW
authors.lastname: Denning
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D000908:Antibodies, Fungal / Q000032:analysis; D001228:Aspergillosis / Q000175:diagnosis / Q000188:drug therapy* / Q000382:microbiology; D001232:Aspergillus fumigatus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D003550:Cystic Fibrosis / Q000150:complications / Q000382:microbiology* / Q000503:physiopathology; D004271:DNA, Fungal / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000382:microbiology; D060888:Real-Time Polymerase Chain Reaction; D013183:Sputum / Q000382:microbiology*; D016896:Treatment Outcome; D014797:Vital Capacity
chemical_list: D000900:Anti-Bacterial Agents; D000908:Antibodies, Fungal; D004271:DNA, Fungal
keywords: Aspergillus Lung Disease; Cystic Fibrosis; Respiratory Infection