lmonary function tests, nutritional status, and exercise tolerance. Microbial eradication is not a therapeudic end point. Choice of antibiotics should be based on culture and sensitivity of the sputum. Emergence of antibiotic-resistant species, such as Pseudomonas aeruginosa, has required close monitoring of antibiotic susceptibility patterns and strict infection-control policies. Administration of chronic intermittent inhaled antipseudomonal therapy (tobramycin solution for inhalation), over a 6 month period was shown to improve FEV by 11.9%, decrease the bacterial density, and reduce hospitalization in CF patients chronically infected with Pseudomonas aeruginosa. Following 92 weeks of therapy with inhaled tobramycin, the mean % change in FEV was 4.7% above baseline. There was no increase in the utilization of antipseudomonal therapy despite an increase in MIC at the end of 12 treatment cycles. Decreases in Pseudomonas aeruginosa tobramycin susceptibility were not predictive of a lack of clinical response, i.e. lung function, to inhaled tobramycin. A potential role for aggressive antipseudomonal therapy that is currently under study involves the use of inhaled tobramycin in young patients at the time of initial colonization. Researchers are hopeful that early, aggressive intervention may be effective in eradication of Pseudomonas aeruginosa, and therefore, will have a dramatic impact on the natural history of cystic fibrosis. One of the major factors that makes Pseudomonas aeruginosa difficult to eradicate is the overproduction of a sugar-like substance, alginate. One of the regulators of alginate production, the AlgR protein, has recently been shown to be involved with the function of pili (tiny hair-like appendages on the outside of the bacteria). Pili are involved in the initial stages of Pseudomonas aeruginosa infection of CF lungs. The AlgR protein, thus, may regulate not only genes controlling alginate produ...
