Direct antimicrobial susceptibility testing method for analysis of sputum collected from patients with cystic fibrosis.

Background: Chronic Pseudomonas aeruginosa colonisation and subsequent exacerbations in patients with cystic fibrosis (CF) require antimicrobial treatment. But since multiple morphotypes and other Gram-negative bacteria with different antibiotic susceptibilities are often isolated inside the same sputum sample, bacteriological analysis is difficult.

Methods: To simplify this analysis, we explored a direct sputum antimicrobial susceptibility testing (DSST) method by applying E test directly on plates inoculated with the sputum.