Ciprofloxacin plus erythromycin or ambroxol ameliorates endotracheal tube-associated Pseudomonas aeruginosa biofilms in a rat model

Background and objectivePseudomonas aeruginosa is a multi-drug resistant bacterium, with its biofilm-growing mucoid (alginate-producing) strains being particularly resistant. As atomized drug administration is a common practice in pediatric patients, we compared the effect of inhalational therapy with erythromycin plus ciprofloxacin, with that of ambroxol plus ciprofloxacin, against biofilm producing strains of P. aeruginosa.ResultsBoth combined treatment regimens were associated with a significant reduction in bacterial counts in endotracheal (ET) tubes and lungs, as compared to that observed with ambroxol and erythromycin monotherapies (P < 0.05). Ciprofloxacin plus ambroxol appeared to have a higher efficacy than ciprofloxacin plus erythromycin, both in lowering bacterial counts (P < 0.05) and in disrupting the structural integrity of biofilm. Histopathological changes in the lungs were milder in the two combined treatment groups, as compared to that in groups treated with single drugs.ConclusionErythromycin or ambroxol in combination with ciprofloxacin could eliminate P. aeruginosa biofilms. When combined with ciprofloxacin, ambroxol outperformed erythromycin in eradicating P. aeruginosa biofilm.