Influence of Moxifloxacin,Comparator Drugs and Some Fractions of Pulmonary Surfactant on Adherence of Some Respiratory Pathogens

Background: This study evaluated the effect of moxifloxacin and comparator drugs with or without some fractions of pulmonary surfactant, as surfactant protein-A (SP-A) and phospholipids, on the adherence of the most common respiratory pathogens. Materials and Methods: The adherence of respiratory pathogens to a bronchial epithelial cell line was tested. Antimicrobials were used at 1/2, 1/4 and 1/8 minimum inhibitory concentration (MIC), SP-A at 1 and 5 μg/ml and phospholipids at 50 μg/ml. Results: At 1/2 MIC moxifloxacin, ciprofloxacin, amoxicillin-clavunalate and ceftriaxone reduced the adherence of Staphylococcus aureus and Streptococcus pneumoniae to values of 40-50%. At the same concentration, cotrimoxazole reduced the adherence values of Moraxella catarrhalis and Haemophilus influenzae to about 50%, while β-lactams showed high efficacy only on H. influenzae, with adherence values of about 40%. The addition of SP-A and/or phospholipids to the tested antibiotics had no effect on bacterial adherence. Conclusion: The non-interference of SP-A and/or phospholipids with the suppressive effect that some antibiotics exert on bacterial adherence could represent a favorable event during antibiotic therapy. Received: March 23, 2001·Revision accepted: May 10, 2002