Cystic Fibrosis Pathogens and Management

Prevalence and Characteristics of Major Pathogens

Pseudomonas aeruginosa is the most frequent pathogen isolated from cystic fibrosis sputum or bronchoalveolar lavage samples across all age groups, followed by Staphylococcus aureus 1, 2
Prevalence of P. aeruginosa increases with age: 29.8% in children aged 2-5 years and 81.3% in adults aged 26-30 years 1
Overall incidence of P. aeruginosa infections in CF is estimated at 8% 1
Chronic P. aeruginosa infection is associated with more rapid reduction in lung function and poorer prognosis 3

P. aeruginosa lung infection should be assessed by collecting sputum with minimal saliva contamination 3
In non-sputum producers, hypopharyngeal or endolaryngeal suctions should be taken, preferably after lung physiotherapy or hypertonic saline inhalation 3
P. aeruginosa grows well on standard laboratory media such as 5% sheep blood agar or chocolate agar 2
Selective media, such as cetrimide agar, facilitate the isolation of P. aeruginosa from other bacterial species 2
Periodic serological tests for P. aeruginosa antigens should be used in non-sputum producers to avoid false-negative results 3
Colonization/infection should be assessed as early as possible, at least every three months 3

The majority of CF patients carrying mucoid P. aeruginosa experience an immediate and more rapid reduction of lung function compared to those without P. aeruginosa infection 3
Pulmonary infection has been recognized as having the greatest role in morbidity and mortality, leading to premature death in 90% of CF patients 1
Antipseudomonal therapy is generally warranted in CF patients and affects survival to an extent that is not fully quantified 3
CF centers have implemented separation of patients with and without P. aeruginosa infection to limit cross-infection 1
Hygienic measures to decontaminate environmental reservoirs of P. aeruginosa are recommended 1
Hand disinfection for CF patients and hospital personnel is important 1
Combination antibiotic therapy with two different drugs is preferred over monotherapy to delay development of antibiotic resistance 3