Tobramycin Activity for Pseudomonas Aeruginosa spp. Isolated in Cystic Fibrosis Patients

Study Objective: To determine in vitro activity of Tobramycin for Pseudomonas aeruginosa spp. isolated in children with cystic fibrosis (CF); to retrospectively study the efficiency dynamics of inhalative Tobramycin in management of bronchopulmonary process exacerbation in children with CF aged 9 years old (2009–2018). Study Design: retrospective analysis. Materials and Methods. The study included 173 children with cystic fibrosis aged 3 to 17 years old; the median age in the general group was 11 [8; 15] years. Subjects were divided into two comparison groups, depending on various 14-day combined antipseudomonal therapy: 42 children were treated with Cefepime 150 mg/kg + Amikacin 20 mg/kg IV drop infusion; 48 subjects — with Meropenem 100 mg/kg + Amikacin 20 mg/kg IV drop infusion; 83 patients — with Ceftazidime 200 mg/kg IV + Tobramycin (Bramitob) 300 mg twice daily, inhalation + Ciprofloxacin per os 30–40 mg/kg. Study Results. After the two-week therapy of 83 children with Tobramycin inhalations plus oral Ciprofloxacin and Ceftazidime IV, 123 (82%) out of 150 pathogenic P. aeruginosa and Staphylococcus aureus spp. were eliminated (p < 0.001 when compared to bacteriologic test results of pre-therapy bronchial mucus). Comparison groups demonstrated statistically significantly lower number of such subjects: in Cefepime + Amikacin group, 32 (43.8%) out of 73 pathogenic P. aeruginosa and S. aureus spp. were eliminated; whereas in Meropenem + Amikacin group, only 28 (35.4%) pathogens were eliminated out of 79 species. Upon admission in 2013, 50 followed up children underwent antimicrobial therapy with inhalative Tobramycin using the same regimen as in 2009; the P. aeruginosa elimination was the same: 11 (18%) out of 61 pathogenic species remained viable, 50 (82%) species were eliminated, as demonstrated by control sputum. The difference between the number of P. aeruginosa and S. aureus colonies before and after therapy was statistically significant (p < 0.001). Practically the same result after the use of inhalative Tobramycin was observed in 2018: 14 (70%) out 20 children with P. aeruginosa spp. had their control sputum samples sanitised (p < 0.001). Conclusion. Despite a 20-year history of using in patients with cystic fibrosis, inhalative Tobramycin is still clinically efficient and potent for isolated P. aeruginosa as a component of primary eradication and management of chronic Pseudomonal lung infections. Keywords: cystic fibrosis, Pseudomonas aeruginosa, inhalative Tobramycin.