A diagnostic PCR assay for the detection of an Australian epidemic strain of <it>Pseudomonas aeruginosa</it>

• Main Authors: Murphy Anna, Thomas Susan J, Turnbull Lynne, Williams Heidi L, Stinear Tim, Armstrong David S, Whitchurch Cynthia B
• Format: Article
• Language: English
• Published: BMC 2010-07-01
• Series: Annals of Clinical Microbiology and Antimicrobials
• Online Access: http://www.ann-clinmicrob.com/content/9/1/18

<p>Abstract</p> <p>Background</p> <p>Chronic lung infection with the bacterium <it>Pseudomonas aeruginosa </it>is one of the hallmarks of cystic fibrosis (CF) and is associated with worsening lung function, increased hospitalisation and reduced life expectancy. A virulent clonal strain of <it>P. aeruginosa </it>(Australian epidemic strain I; AES-I) has been found to be widespread in CF patients in eastern Australia.</p> <p>Methods</p> <p>Suppression subtractive hybridization (SSH) was employed to identify genetic sequences that are present in the AES-I strain but absent from the sequenced reference strain PAO1. We used PCR to evaluate the distribution of several of the AES-I loci amongst a collection of 188 <it>P. aeruginosa </it>isolates which was comprised of 35 AES-I isolates (as determined by PFGE), 78 non-AES-I CF isolates including other epidemic CF strains as well as 69 <it>P. aeruginosa </it>isolates from other clinical and environmental sources.</p> <p>Results</p> <p>We have identified a unique AES-I genetic locus that is present in all 35 AES-I isolates tested and not present in any of the other 153 <it>P. aeruginosa </it>strains examined. We have used this unique AES-I locus to develop a diagnostic PCR and a real-time PCR assay to detect the presence of <it>P. aeruginosa </it>and AES-I in patient sputum samples.</p> <p>Conclusions</p> <p>We have developed diagnostic PCR assays that are 100% sensitive and 100% specific for the <it>P. aeruginosa </it>strain AES-I. We have also shown that Whatman FTA^®Elute cards may be used with PCR-based assays to rapidly detect the presence of <it>P. aeruginosa </it>strains in CF sputum.</p>