Adult Cystic Fibrosis Exacerbations and New Strains of Pseudomonas aeruginosa

Abstract

We hypothesized that in adults with cystic fibrosis, the acquisition of a new strain of Pseudomonas aeruginosa may be associated with a pulmonary exacerbation. Eighty-four patients who were chronically infected with P. aeruginosa were prospectively followed from eight centers over a 26-month period. Patients had sputum cultures performed every 3 months while clinically stable and at the time of an exacerbation. Forty patients (48%) had an exacerbation requiring intravenous antibiotics during the study period, and in 36 of these patients, their P. aeruginosa isolates were genetically typeable by pulsed-field gel electrophoresis. In 34 of the 36 patients (94%), P. aeruginosa recovered during clinical stability and at exacerbation were of the same genotype. In only two patients (6%; 95% confidence interval, 0-18%) was a new P. aeruginosa clone cultured during an exacerbation that had not been cultured during clinical stability. There were no significant differences in antibiotic susceptibilities, measured as mean minimal inhibitory concentrations, for isolates retrieved during clinically stable periods compared with isolates retrieved during exacerbations. We conclude that for the majority of adult patients with cystic fibrosis a new pulmonary exacerbation is not caused by the acquisition of a new strain of P. aeruginosa.

Pseudomonas aeruginosa Flagellin and Alginate Elicit Very Distinct Gene Expression Patterns in Airway Epithelial Cells: Implications for Cystic Fibrosis Disease

“…Remarkably, this study shows that the interaction between oropharyngeal flora and P. aeruginosa in CF results specifically in the up-regulation of fliC expression. In this context, our study suggests that the underlying cause of the exacerbations frequently observed in adult CF patients, which are not the result of acquisition of new strains (74), may be the potent proinflammatory activity of flagellin. …”

Twenty-Five-Year Outbreak of Pseudomonas aeruginosa Infecting Individuals with Cystic Fibrosis: Identification of the Prairie Epidemic Strain

“…The identification of a high degree of concordance in infecting strains at FE and RE does not strictly rule out the possibility of a transient infection with other strains during time points not assessed. However, the clinical impact of such a transient infection is unlikely to be significant, as exacerbations are not attributed to newly acquired strains (55). While PES isolates were not observed with different PFGE profiles, this remains a possibility that may have led to an underestimate of prevalence.…”

Chronic pulmonary pseudomonal infection in patients with cystic fibrosis: A model for early phase symbiotic evolution

“…Longitudinal bacterial culture following patient disease progression suggests that a gradual decrease in bacterial diversity is associated with an increase in patient age and advanced pulmonary disease (Cox et al, 2010). Transmission of CF airway adapted strains, for example, a hyper-mucoid Pa, has never been reported (Aaron et al, 2004(Aaron et al, , 2010Feliziani et al, 2010;Furukawa et al, 2006;Hogardt et al, 2007;Oliver & Mena, 2010).…”