Analysis of the Efficacy of Eradication Therapy Regimens for the First Isolation of Pseudomonas aeruginosa

Microbial inflammation caused by P. aeruginosa is associated with low lung function, inadequate nutritional status, severe disease course, the presence of respiratory complications and early mortality. The window of opportunity for eradication is the early detection of colonization of P. aeruginosa in the respiratory tract. The highest chance of completely eradicating P. aeruginosa exists if treatment is started in the first month after its detection.

Objective. To evaluate the strategies of inhaled antibiotic therapy in children with cystic fibrosis when P. aeruginosa is initially detected in the sputum.

Materials. The study included pediatric patients with CF who were observed in the Department of Cystic Fibrosis of the Moscow Regional Research Institute of Childhood of the Ministry of Health of the Moscow Region. The number of patients with the first isolation of P. aeruginosa among patients in the Moscow Region during the 4-year follow-up period was 37 children (19 males / 18 females). The median age of the children was 4.87 (3.33; 9.9) years. 89% of the patients had a ‘’severe genotype’’. The median age of diagnosis was Me (Q1; Q3) 0.2 (0.1; 0.2) years. All children underwent microbiological monitoring on a regular basis, once a quarter, before inclusion in the study.

Results. Patients on inhaled tobramycin or colistimethate sodium in combination with ciprofloxacin had a 100% positive result in both cases, with all children achieving eradication during follow-up for 2 years or more. A high percentage of eradication was achieved in patients receiving inhaled tobramycin therapy, with 93.3% achieving persistent eradication. Lower rates were observed in patients receiving only sodium colistimethate inhalation therapy, with 75% achieving eradication, and in patients alternating between inhaled tobramycin and sodium colistimethate, with 66.6% achieving eradication. However, a statistical analysis of the results of the effectiveness of the antibacterial therapy schemes did not show any advantage of any of the schemes (p = 0.94). Patients with primary P. aeruginosa isolation showed better external respiratory function results one year after eradication therapy compared to patients with chronic P. aeruginosa – Me (Q1; Q3) FEV1 (p1-2 = 0.004), FVC (p1-2 = 0.039). Children who underwent eradication therapy had a statistical difference in terms of nutritional status according to the BMI percentile – Me (Q1; Q3) per BMI kg/m² compared to the group with chronic P. aeruginosa (p1-2 = 0.016).

Conclusion. Early eradication therapy at the first P. aeruginosa isolation helps to prevent chronic infection, avoid lung function decline, structural damage to the lungs, and delay chronic colonization. Early start of eradication therapy depends on constant regular microbiological monitoring, which requires a modern organization of dynamic monitoring of patients with cystic fibrosis.

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