Table 1.
Microbiological patterns and criteria in pulmonary Pseudomonas aeruginosa colonization/infection in cystic fibrosis patients
| Infection/colonization | Definition | Microbiological criteria | Comments |
|---|---|---|---|
| I. Initial colonization (first colonization event or pioneer colonization) | Detection of the first positive P. aeruginosa culture in the bronchial tree. No clinical symptoms | First positive P. aeruginosa culture | A positive culture following 1 year of negative cultures after finishing treatment is considered as a new initial colonization. The strains are usually nonmucoid colonies, with little diversity in morphotypes or antimicrobial susceptibilities |
| II. Sporadic or intermittent colonization | Intermittent presence of positive and negative P. aeruginosa cultures in consecutive samples after initial colonization. No signs of infection | Detection, within a period of 6 months of the initial colonization, of a positive P. aeruginosa culture among at least three cultures, with at least 1 month between each positive culture | Possible recovery of strains with mucoid colonies and other colonial morphotypes |
| III. Colonization with bronchopulmonary infection | Initial or sporadic colonization with presentation of clinical signs of infection | As for initial or sporadic colonization | In patients without microbiological specimens, the appearance or increase of antibodies in two successive blood samples, with at least 3 months between each sample, can be used as a diagnostic criterion |
| IV. Chronic colonization | Persistent positive P. aeruginosa cultures without new clinical signs of infection | Detection within a period of 6 months of a minimum of three positive P. aeruginosa cultures, with at least 1 month between the positive cultures | Usually produced by strains with mucoid colonies and other colonial morphotypes. This is the common pattern during advanced periods of the disease |
| V. Chronic bronchopulmonary infection (exacerbation) | Presentation of clinical signs of infection during the course of a chronic colonization | As for chronic colonization | In patients with microbiological specimens, an increase of antibodies in two successive blood samples can be used as a diagnostic criterion |
Copyright © 2005, Wiley. Adapted with permission from Cantón R, Cobos N, de Gracia J, et al. Antimicrobial therapy for pulmonary pathogenic colonisation and infection by Pseudomonas aeruginosa in cystic fibrosis patients.Clin Microbiol Infect. 2005;11(9):690–703.