RT Journal Article
SR Electronic
T1 Concordant genotype of upper and lower airways <em>P aeruginosa</em> and <em>S aureus</em> isolates in cystic fibrosis
JF Thorax
JO Thorax
FD BMJ Publishing Group Ltd and British Thoracic Society
SP 535
OP 540
DO 10.1136/thx.2008.104711
VO 64
IS 6
A1 J G Mainz
A1 L Naehrlich
A1 M Schien
A1 M Käding
A1 I Schiller
A1 S Mayr
A1 G Schneider
A1 B Wiedemann
A1 L Wiehlmann
A1 N Cramer
A1 W Pfister
A1 B C Kahl
A1 J F Beck
A1 B Tümmler
YR 2009
UL http://thorax.bmj.com/content/64/6/535.abstract
AB Rationale: Lower airway (LAW) infection with Pseudomonas aeruginosa and Staphylococcus aureus is the leading cause of morbidity in cystic fibrosis (CF). The upper airways (UAW) were shown to be a gateway for acquisition of opportunistic bacteria and to act as a reservoir for them. Therefore, tools for UAW assessment within CF routine care require evaluation.Objectives: The aims of the study were non-invasive assessment of UAW and LAW microbial colonisation, and genotyping of P aeruginosa and S aureus strains from both segments.Methods: 182 patients with CF were evaluated (age 0.4–68 years, median 17 years). LAW specimens were preferably sampled as expectorated sputum and UAW specimens by nasal lavage. P aeruginosa and S aureus isolates were typed by informative single nucleotide polymorphisms (SNPs) or by spa typing, respectively.Results: Of the typable S aureus and P aeruginosa isolates from concomitant UAW- and LAW-positive specimens, 31 of 36 patients were carrying identical S aureus spa types and 23 of 24 patients identical P aeruginosa SNP genotypes in both compartments. Detection of S aureus or P aeruginosa in LAW specimens was associated with a 15- or 88-fold higher likelihood also to identify S aureus or P aeruginosa in a UAW specimen from the same patient.Conclusions: The presence of identical genotypes in UAW and LAW suggests that the UAW play a role as a reservoir of S aureus and P aeruginosa in CF. Nasal lavage appears to be suitable for non-invasive UAW sampling, but further longitudinal analyses and comparison with invasive methods are required. While UAW bacterial colonisation is typically not assessed in regular CF care, the data challenge the need to discuss diagnostic and therapeutic standards for this airway compartment.Trial registration number: NCT00266474.