Sputum samples from Monash Medical Centre CF clinic patients that were positive or negative for the AES-I strain as determined by PFGE, were swabbed onto Whatman FTA® Elute cards, DNA eluted and used in the oprL PCR assay to determine the presence of P. aeruginosa in the sputum sample and in a 2nd PCR assay with the HW2 AES-I primers to determine if the P. aeruginosa present in the sputum was AES-I (Fig 1). This evidence concerns the gene TLE5 and cystic fibrosis.