Emergence of a shared Pseudomonas aeruginosa strain within an adult cystic fibrosis centre

Abstract

Objectives: During a prevalence study of patients attending a single, large Australian adult CF centre in 2007/2008 we demonstrated that 124/171 (73%) harboured ≥1 shared P. aeruginosa strain. Three predominant genotypes, AUST-01, AUST-02 and AUST-06 were detected in 21 (12%), 69 (40%) and 17 (10%) patients, respectively. Despite the overall data reflecting earlier work in 2001/2002, the prevalence AUST-06 appeared to increase overtime. Here we explored the longitudinal prevalence of shared strain infections in this adult CF centre between 2007/2009 and 2012/2014. Methods: Sputum was collected annually from all patients and 3 P. aeruginosa colonies representing different morphotypes were selected from each culture positive sample for genotyping by Sequenom iPLEX MALDI-TOF SNP-typing and ERIC-PCR fingerprint analysis. Results: Overall, 276 patients contributed ≥1 positive P. aeruginosa culture over the study period. Proportions of patients harbouring AUST-02 declined over time, (69/171 [40%] 2007/2008 vs. 58/217 [27%] 2012/2013; p = 0.006), while increasing for AUST-06 (17/171 [10%] 2007/2008 vs. 55/217 [25%] 2012/2013; p < 0.001). In contrast, the prevalence of AUST-01 remained stable (21/171 [12%] 2007/2008 vs. 26/217 [10%] 2012/2013; p = 0.754). Of the confirmed 28 AUST-06 incident cases, 75% comprised patients managed within the CF centre throughout the entire study period. Conclusion: We observed a shift in epidemiology of shared strain infections among adult patients with CF at a time where infection control practices were not changed. Investigation of the potential reasons for the emergence of and clinical significance of the AUST-06 strain is underway.L6143235082017-02-10 <br />